Dysmorphology and Chromosomal abnormalities

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Questions and Answers

What is the chromosomal notation for Trisomy 18?

46, XY +18

47, XY +18 (correct)

46, XX +18

47, XX +18 (correct)

What is a common renal anomaly associated with Trisomy 18?

Cystic kidney disease

Renal agenesis

Polycystic kidney disease

Horseshoe kidney (correct)

Which of the following is NOT a characteristic feature of Cri Du Chat Syndrome?

Ocular hypertelorism

Hypotonia

Streak gonads (correct)

Clefts of the lip and palate

Which of the following treatments is ineffective in correcting infertility due to Turner Syndrome?

Estrogen replacement therapy Signup and view all the answers

What language describes the characteristic sound associated with Cri Du Chat Syndrome?

Crying Signup and view all the answers

Which craniofacial features are associated with Trisomy 13?

Microcephaly with sloping forehead and broad triangular nose Signup and view all the answers

What percentage of Trisomy 13 cases typically exhibit cleft lip and palate?

60-80% Signup and view all the answers

Which of the following is a common cardiac abnormality associated with Trisomy 13?

Ventricular Septal Defect (VSD) Signup and view all the answers

Which extremity abnormality is commonly seen in individuals with Trisomy 13?

Clinodactyly and polydactyly Signup and view all the answers

What general developmental issue is often associated with Trisomy 13?

Severe developmental delays and growth retardation Signup and view all the answers

At what age is it crucial to observe the persistence of specific facial features associated with certain disorders?

At 12 years Signup and view all the answers

Which of the following features are included in the assessment for dysmorphic syndromes?

Hypoplastic philtrum Signup and view all the answers

Which reference material includes information on fetal alcohol spectrum disorders?

Williams Obstetrics Signup and view all the answers

Which publication discusses the genetics and dysmorphology relevant to pediatric patients?

Medical Genetics: An Integrated Approach Signup and view all the answers

Which combination of facial features is primarily associated with dysmorphic conditions?

Flat midface and thin upper vermilion border Signup and view all the answers

What is the primary cause of Fragile X Syndrome?

Expanded trinucleotide repeats Signup and view all the answers

Which feature is characteristic of Fetal Alcohol Syndrome?

Midface hypoplasia and smooth philtrum Signup and view all the answers

How is Fetal Alcohol Syndrome typically diagnosed?

Prenatal and postnatal growth retardaion Signup and view all the answers

What is the most common teratogenic syndrome?

Fetal Alcohol Syndrome Signup and view all the answers

Which of the following is NOT a neurobehavioral profile feature of Fragile X Syndrome?

Learning disability in mathematics Signup and view all the answers

What is the recommended level of alcohol intake during pregnancy to avoid Fetal Alcohol Syndrome?

6 oz of alcohol each day Signup and view all the answers

Which craniofacial finding is associated with Fragile X Syndrome?

Large head Signup and view all the answers

What percentage of birth defects are attributed to teratogens?

6.5% Signup and view all the answers

What condition is characterized by a head shape that is shortened from front to back along the sagittal plane?

Brachycephaly Signup and view all the answers

Which of the following describes a condition in which the distance between the pupils of the eyes is increased?

Ocular Hypertelorism Signup and view all the answers

What term describes the fleshy tissue of the nose that separates the nostrils?

Columella Signup and view all the answers

Which condition involves a deficiency in the number of digits?

Oligodactyly Signup and view all the answers

What is the term for a groove that extends from the margin of the nasal alae to the lateral aspects of the lips?

Nasolabial fold Signup and view all the answers

Which chromosomal disorder is also known as Patau Syndrome?

Trisomy 13 Signup and view all the answers

What is a key feature of Trisomy 13 that indicates its diagnosis when accompanied by polydactyly?

Aplasia Cutis Congenita Signup and view all the answers

Which condition involves an elongated head shape from front to back?

Scaphocephaly Signup and view all the answers

What term is used to describe short digits?

Brachydactyly Signup and view all the answers

What is the condition characterized by eyebrows that meet in the midline?

Synophrys Signup and view all the answers

What percentage of individuals with Trisomy 13 is likely to have congenital heart disease?

80% Signup and view all the answers

Which of the following is a common renal abnormality associated with Trisomy 13?

Renal abnormalities Signup and view all the answers

Which craniofacial characteristic is NOT typically observed in individuals with Trisomy 13?

Prominent forehead Signup and view all the answers

What is a notable feature of hand abnormalities in Trisomy 13?

Clinodactyly Signup and view all the answers

Severe developmental delays associated with Trisomy 13 are likely to be indicated by which of the following?

Severe developmental delays Signup and view all the answers

What is the most common renal anomaly associated with Trisomy 18?

Horseshoe kidney Signup and view all the answers

What is a significant effect of Turner Syndrome on sexual development?

Hypogonadism leading to estrogen deficiency Signup and view all the answers

Which of the following features is NOT commonly associated with Cri Du Chat Syndrome?

Optic nerve hypoplasia Signup and view all the answers

What is a common outcome for individuals with Turner Syndrome regarding reproduction?

Inability to conceive despite treatment Signup and view all the answers

What is associated with the severity of Cri Du Chat Syndrome?

Size of the genetic deletion on chromosome 5 Signup and view all the answers

At what age should specific facial features indicating certain disorders be noted for persistence?

At 2½ years Signup and view all the answers

Which of the following features is NOT associated with Fetal Alcohol Syndrome?

Tall stature Signup and view all the answers

Which of these features is typically noted in the assessment of dysmorphic syndromes?

Short palpebral fissures Signup and view all the answers

Which craniofacial characteristic is often associated with Fetal Alcohol Spectrum Disorders?

Flat midface Signup and view all the answers

What specific facial feature is characterized by a lower lip that is thin and poorly defined?

Thin upper vermilion border Signup and view all the answers

What is the most prevalent genetic disorder associated with inherited mental retardation?

Fragile X Syndrome Signup and view all the answers

Which physical characteristic is commonly associated with Fragile X Syndrome?

Large head Signup and view all the answers

What is considered a key feature of Fetal Alcohol Syndrome?

Short palpebral fissures Signup and view all the answers

Which of the following factors is considered a teratogen during pregnancy?

Intrauterine infections Signup and view all the answers

What is the recommended daily alcohol intake during pregnancy to avoid Fetal Alcohol Syndrome?

6 oz Signup and view all the answers

Which of the following is a potential outcome from teratogen exposure during pregnancy?

Congenital malformations Signup and view all the answers

Which skeletal abnormality is associated with Fetal Alcohol Syndrome?

Clinodactyly of the fifth fingers Signup and view all the answers

What is the ratio of children affected by Fetal Alcohol Syndrome?

10-20:1000 Signup and view all the answers

What is the term that describes the condition characterized by the spacing of the eyes?

Telorism Signup and view all the answers

What describes the condition of having an unusually small nail on a digit?

Hypoplastic Nail Signup and view all the answers

Which condition is indicated by an asymmetric head shape due to suture closure or uneven brain growth?

Plagiocephaly Signup and view all the answers

What is the key characteristic of the condition known as synophrys?

Eyebrows that meet in the midline Signup and view all the answers

Which term best describes the condition in which digits are partially fused?

Syndactyly Signup and view all the answers

What craniofacial defect is indicative of Trisomy 13 when accompanied by polydactyly?

Aplasia Cutis Congenita Signup and view all the answers

In which condition is there an increased distance between the inner canthi of the eyes?

Telecanthus Signup and view all the answers

Which term refers to a condition of having six or more digits on an extremity?

Polydactyly Signup and view all the answers

What is the defining characteristic of brachycephaly?

Shortened head shape from front to back Signup and view all the answers

Which condition involves a crooked digit that curves towards adjacent digits?

Clinodactyly Signup and view all the answers

Which of the following is a craniofacial feature commonly observed in individuals with Trisomy 13?

Broad triangular nose Signup and view all the answers

What percentage of patients with Trisomy 13 typically experience congenital heart disease?

80% Signup and view all the answers

Which of the following conditions is associated with overlapping fingers in patients with Trisomy 13?

Clinodactyly Signup and view all the answers

What is a significant renal abnormality often associated with Trisomy 13?

Hypoplastic kidneys Signup and view all the answers

Which feature is commonly associated with severe developmental delays seen in Trisomy 13?

Low muscle tone Signup and view all the answers

What is a key characteristic of Turner Syndrome?

Streak gonads leading to estrogen deficiency Signup and view all the answers

Which of the following features is most closely related to Cri Du Chat Syndrome?

Ocular hypertelorism Signup and view all the answers

Trisomy 18 is most frequently characterized by which of the following?

5 times higher risk of hypothyroidism Signup and view all the answers

What impact does Turner Syndrome have on reproduction?

Infertility that persists despite estrogen treatment Signup and view all the answers

Which statement regarding Cri Du Chat Syndrome is accurate?

Larger deletions usually lead to more severe symptoms Signup and view all the answers

What is one of the most prominent craniofacial features associated with Fragile X Syndrome?

Prominent forehead Signup and view all the answers

What is a key feature of Fetal Alcohol Syndrome?

Short palpebral fissures Signup and view all the answers

Which statement about the effects of teratogens is correct?

They can lead to congenital malformations. Signup and view all the answers

Which demographic is most severely affected by Fragile X Syndrome?

Genetic males Signup and view all the answers

What is the recommended minimum alcohol consumption during pregnancy associated with fetal alcohol syndrome?

6 oz per day Signup and view all the answers

What percentage of all birth defects is attributed to teratogenic effects?

6.5% Signup and view all the answers

Which of these is a characteristic behavioral profile feature of Fragile X Syndrome?

Hyperactivity Signup and view all the answers

Which growth characteristic is typically seen in children with Fetal Alcohol Syndrome?

Weight below the 10th percentile Signup and view all the answers

At what age should the persistence of specific facial features be noted for conditions related to fetal alcohol spectrum disorders?

At 2½ years Signup and view all the answers

Which of the following features is indicative of fetal alcohol syndrome?

Short palpebral fissures Signup and view all the answers

Which abnormality is commonly observed in the craniofacial structure associated with fetal alcohol spectrum disorders?

Epicanthal folds Signup and view all the answers

What does a hypoplastic philtrum indicate in relation to fetal alcohol spectrum disorders?

Significant teratogenic effect Signup and view all the answers

Which craniofacial feature is most frequently noted in individuals with fetal alcohol syndrome?

Thin upper vermilion border Signup and view all the answers

What is the medical term for a condition characterized by short digits?

Brachydactyly Signup and view all the answers

Which term describes an increased distance between the pupils of the eyes?

Ocular Hypertelorism Signup and view all the answers

What is the term used for the vertical groove in the midline of the face between the nose and the upper lip?

Philtrum Signup and view all the answers

Which condition involves the abnormal fusion of two or more digits?

Syndactyly Signup and view all the answers

Which of the following is a key clinical feature of Trisomy 13?

Palpebral fissure abnormalities Signup and view all the answers

What is the craniofacial feature characterized by a sloping forehead and malformed ears?

Cebocephaly Signup and view all the answers

Which condition is indicated by the acronym 'XO' in its chromosomal notation?

Turner’s Syndrome Signup and view all the answers

Which of the following is NOT a common feature of Trisomy 18?

Polydactyly Signup and view all the answers

What is the name of the condition where the head shape is elongated from front to back?

Scaphocephaly Signup and view all the answers

Which condition is defined as a deficiency in the number of digits?

Oligodactyly Signup and view all the answers

Which of the following is a common craniofacial feature of Trisomy 13?

Broad triangular nose Signup and view all the answers

What percentage of cases of Trisomy 13 typically exhibit congenital heart disease?

80% Signup and view all the answers

Which of the following extremity abnormalities is associated with Trisomy 13?

Overlapping fingers Signup and view all the answers

What is a common neurological outcome for individuals with Trisomy 13?

Severe developmental delays Signup and view all the answers

Which of the following renal abnormalities is associated with Trisomy 13?

Renal agenesis Signup and view all the answers

Which of the following conditions results from a deletion on the short arm of chromosome 5?

Cri Du Chat Syndrome Signup and view all the answers

What is a key developmental issue often observed in individuals with Cri Du Chat Syndrome?

Hypotonia Signup and view all the answers

Which characteristic is associated with Turner Syndrome due to the presence of streak gonads?

Estrogen deficiency Signup and view all the answers

Which of the following features is indicative of a larger deletion in Cri Du Chat Syndrome?

Tracheal hypoplasia Signup and view all the answers

Which congenital issue is noted to be five times more likely in individuals with Trisomy 18?

Hypothyroidism Signup and view all the answers

What specific facial feature is linked to Fetal Alcohol Spectrum Disorders?

Short palpebral fissures Signup and view all the answers

At what age are the facial features associated with certain disorders typically observed for persistence?

At 2½ years Signup and view all the answers

Which of the following features is NOT typically associated with Fetal Alcohol Spectrum Disorders?

Protruding chin Signup and view all the answers

Which statement best describes the impact of facial features related to Fetal Alcohol Spectrum Disorders?

They can influence social interactions and emotional development. Signup and view all the answers

Which of the following is a characteristic manifestation of Fetal Alcohol Spectrum Disorders?

Short palpebral fissures Signup and view all the answers

What is a common craniofacial feature associated with Fragile X Syndrome?

Prominent forehead Signup and view all the answers

Which statement about Fragile X Syndrome is true?

It is the most common cause of inherited mental retardation. Signup and view all the answers

What is a key characteristic of Fetal Alcohol Syndrome?

Craniofacial abnormalities Signup and view all the answers

Which teratogenic disorder is most common and requires significant alcohol consumption during pregnancy for full development?

Fetal Alcohol Syndrome Signup and view all the answers

Which feature is NOT typically associated with Fetal Alcohol Syndrome?

Macro-orchidism Signup and view all the answers

What is the association between teratogens and congenital malformations?

Teratogens can damage embryonic tissue leading to malformations. Signup and view all the answers

What percentage of birth defects is attributed to teratogens?

6.5% Signup and view all the answers

Which cognitive performance issue is associated with Fetal Alcohol Syndrome?

Cognitive impairment Signup and view all the answers

What is the condition characterized by a head shape that is asymmetric in the sagittal or coronal planes?

Plagiocephaly Signup and view all the answers

Which term describes the lateral angle of the eye formed by the junction of the upper and lower eyelids?

Canthus Signup and view all the answers

Which condition is defined by having two or more digits that are at least partially fused?

Syndactyly Signup and view all the answers

What is the significant clinical manifestation associated with Trisomy 13 when accompanied by polydactyly?

Aplasia cutis congenita Signup and view all the answers

Which term describes the separation of the nostrils by the fleshy tissue of the nose?

Columella Signup and view all the answers

Which dysmorphology term refers to short digits?

Brachydactyly Signup and view all the answers

Which feature is commonly associated with Ocular Hypertelorism?

Increased distance between the pupils Signup and view all the answers

Which term refers to the groove extending from the margin of the nasal alae to the lips?

Philtrum Signup and view all the answers

Which chromosomal condition is also identified as Klinefelter's Syndrome?

XXY Signup and view all the answers

What is the primary reason for the increased risk of congenital heart disease in individuals with Trisomy 13?

Genetic predisposition Signup and view all the answers

Study Notes

Terms Pertaining to the Face and Head

Brachycephaly: Head shape is shortened from front to back along the sagittal plane, making the skull rounder than normal.
Canthus: The lateral or medial angle of the eye formed by the junction of the upper and lower eyelids.
Columella: The fleshy tissue of the nose that separates the nostrils.
Glabella: The bony midline prominence of the brows.
Nasal Alae: The lateral flaring of the nostrils.
Nasolabial Fold: Groove extending from the margin of the nasal alae to the lateral aspects of the lips.
Telorism: Refers to the spacing of the eyes.
Ocular Hypertelorism: Increased distance between the pupils of the eyes.
Ocular Hypotelorism: Decreased distance between the pupils of the eyes.
Palpebral Fissure: The shape of the eyes based on the outline of the eyelids.
Philtrum: The vertical groove in the midline of the face between the nose and the upper lip.
Plagiocephaly: Asymmetrical head shape in the sagittal or coronal planes. Can be caused by asymmetrical suture closure or brain growth. Positional plagiocephaly is also possible.
Scaphocephaly: Head is elongated from front to back in the sagittal plane. Most normal skulls are slightly scaphocephalic.
Synophrys: Eyebrows that meet in the midline.
Telecanthus: A widened space between the medial canthus (inner canthal distance).

Terms Pertaining to the Extremities

Brachydactyly: Condition of having short digits.
Camptodactyly: A digit is bent or fixed in the direction of flexion, similar to a "trigger finger."
Clinodactyly: A digit is crooked and curves towards or away from adjacent digits.
Hypoplastic Nail: An unusually small nail on a digit.
Melia: Suffix meaning "limb."
- Amelia: Missing limb.
- Brachymelia: Shortened limb.
Oligodactyly: Deficiency in the number of digits.
Polydactyly: Having six or more digits on an extremity.
Syndactyly: Having two or more digits at least partially fused.

Chromosomal Disorders

Trisomy 13: AKA Patau Syndrome. Occurs in 1:12,000 live births, usually fatal within the first year.
- Key features:
  - SGA (small for gestational age) and microcephalic.
  - Midline facial defects - cyclopia, cebocephaly, cleft lip and palate.
  - Sloping forehead, small and malformed ears, micro- or anopthalmia.
  - Polydactyly, clinodactyly, clubfeet, or rocker-bottom feet.
  - Aplasia Cutis Congenita - punched-out scalp lesion over the right or left occiput.
    - This combination of features is almost diagnostic of trisomy 13.
Trisomy 18: AKA Edwards Syndrome. The second most common autosomal trisomy, occurring 1:7,500 live births.
- Key features:
  - Renal anomalies (horseshoe kidney) in 50%.
  - Hypothyroidism 5x more likely.
Trisomy 21 (Down's Syndrome):
Klinefelter's Syndrome (XXY):
Turner's Syndrome (XO):
- Streak gonads (gonadal dysgenesis) instead of well-developed ovaries, leading to estrogen deficiency.
- Premature ovarian failure.
- Amenorrhea and infertility.
- Assisted Reproductive Technology (ART) may help some.
Cri du Chat Syndrome: Deletion on the short arm of chromosome 5 (larger deletions cause more severe symptoms).
- Characteristic "cat-like" cry during infancy due to tracheal hypoplasia.
- Key Features:
  - Low birth weight, postnatal failure to thrive, hypotonia, developmental delays, microcephaly.
  - Craniofacial dysmorphism:
    - Ocular hypertelorism
    - Epicanthal folds
    - Downward obliquity of the palpebral fissures
    - Low-set, malformed ears.
  - Clefts of the lip and palate, congenital heart disease, and other malformations may also occur.
Fragile X Syndrome (FRAX): AKA Martin-Bell Syndrome.
- Caused by an expansion of trinucleotide repeats.
- Occurs in approximately 1:2,000 children.
- Most common cause of inherited mental retardation.
- Genetic males are more severely affected than females.
- Key Features:
  - Craniofacial findings: Large head, prominent forehead, jaw, and ears.
  - Macro-orchidism: Testicular volume twice normal in adulthood.
  - Connective tissue abnormalities.
  - Mitral valve prolapse.
  - Neurobehavioral profile: Mental retardation (from mild to profound), autism spectrum disorder, pervasive developmental disorder.

Teratogenic Disorders

Teratogens: Chemical, physical, or biological agents that have the potential to damage embryonic tissue and result in one or more congenital malformations.
- Examples: Prescription and nonprescription drugs, intrauterine infections, maternal diseases, environmental substances.
Fetal Alcohol Syndrome (FAS):
- Occurs in 10-20:1,000 children.
- The most common teratogenic syndrome.
- Key Features:
  - Prenatal and postnatal growth retardation.
  - Characteristic facial features: Midface hypoplasia, micropthalmia, short palpebral fissures, ptosis, underdeveloped ears (railroad appearance), smooth philtrum, thin upper lip.
  - CNS findings: Microcephaly, intellectual impairment, cognitive impairment, developmental delay (global), irritability in infancy, hyperactivity.
  - Skeletal abnormalities: Clinodactyly of the fifth fingers, camptodactyly, "hockey stick" palmar creases.
  - Functional problems: Myopia, astigmatism, hearing loss.
  - Cardiac defects.

Terms Pertaining to the Face and Head

Brachycephaly: A shortened head shape from front to back, resulting in a rounder skull.
Canthus: The lateral or medial corner of the eye formed by the upper and lower eyelids junction.
Columella: The fleshy tissue separating the nostrils, located on the nose.
Glabella: A bony prominence in the midline of the eyebrows.
Nasal Alae: The lateral flaring of the nostrils, which are the external openings of the nose.
Nasolabial Fold: This groove extends from the nasal ala margin to the lateral aspects of the lips.
Telorism: Refers to the spacing of the eyes:
- Ocular Hypertelorism: Increased distance between the pupils.
- Ocular Hypotelorism: Decreased distance between the pupils.
Palpebral Fissure: Refers to the shape of the eyes based on the outline of the eyelids.
Philtrum: This is the vertical groove in the midline of the face, extending between the nose and upper lip.
Plagiocephaly: An asymmetric head shape in the sagittal or coronal planes, due to asymmetrical suture closure or brain growth. It can also occur as positional plagiocephaly.
Scaphocephaly: An elongated head shape from front to back, in the sagittal plane. Most normal skulls exhibit a slight degree of scaphocephaly.
Synophrys: Unusually joined eyebrows that meet in the midline.
Telecanthus: A widened space between the medial canthus, specifically the inner canthal distance.

Terms Pertaining to the Extremities

Brachydactyly: A condition involving short digits.
Camptodactyly: A digit bent or fixed in a flexed position, resembling a “trigger finger.”
Clinodactyly: A crooked digit that curves towards or away from the adjacent digits.
Hypoplastic Nail: An unusually small nail on a digit.
Melia: A suffix meaning "limb":
- Amelia: Missing limb.
- Brachymelia: Shortened limb.
Oligodactyly: A deficiency in the number of digits.
Polydactyly: Having more than five digits on an extremity, exceeding the usual number.
Syndactyly: Condition of having two or more digits that are at least partially fused.

Chromosomal Disorders

Trisomy 13: Also known as Patau syndrome, this is a chromosomal disorder characterized by the presence of an extra copy of chromosome 13. It occurs in approximately 1:12,000 live births and is typically fatal within the first year of life.
- Key features: SGA (small for gestational age) and microcephaly, midline facial defects including cyclopia, cebocephaly, and cleft lip/palate. Other characteristic features include sloping forehead, small and malformed ears, micro- or anopthalmia, polydactyly, clinodactyly, clubfeet or rocker-bottom feet, and aplasia cutis congenita (punched out scalp lesion over right or left occiput).
Trisomy 18: Also known as Edwards syndrome, this is the second most common autosomal trisomy, occurring in approximately 1:7,500 live births.
- Key features: Renal anomalies are common, including horseshoe kidney, and individuals with Trisomy 18 are more likely to have hypothyroidism.
Trisomy 21 (Down’s Syndrome): This chromosomal disorder is caused by an extra copy of chromosome 21.
Klinefelter’s Syndrome (XXY): Individuals with Klinefelter's syndrome have an extra X chromosome.
Turner’s Syndrome (XO): Individuals with Turner's syndrome have a missing or incomplete X chromosome.
Cri Du Chat Syndrome: This syndrome is caused by a deletion on the short arm of chromosome 5.
- Key features: Low birth weight, postnatal failure to thrive, hypotonia, developmental delay, microcephaly, and craniofacial dysmorphism including ocular hypertelorism, epicanthal folds, downward obliquity of the palpebral fissures, low-set malformed ears. Clefts of the lip and palate, congenital heart disease, and other malformations may be seen.
Fragile X Syndrome (FRAX): This syndrome is caused by an expansion of trinucleotide repeats, affecting approximately 1:2000 children. It is the most common cause of inherited mental retardation.
- Key Features: Craniofacial findings include a large head, prominent forehead, jaw, and ears. Macro-orchidism (testicular volume twice normal in adulthood), connective tissue abnormalities, mitral valve prolapse, and a characteristic neurobehavioral profile including mental retardation (from mild to profound), autism spectrum disorder, and pervasive developmental disorder are common features.

Teratogenic Disorders

These are disorders caused by exposure to teratogens during pregnancy, typically affecting the fetus or embryo. These agents can be chemical, physical, or biological and contribute to approximately 6.5% of all birth defects.
Examples include:
- Prescription and nonprescription drugs
- Intrauterine infections
- Maternal diseases
- Environmental substances
Fetal Alcohol Syndrome: The most common known teratogenic syndrome, affecting 10-20:1000 children.
- Key Features: Prenatal and postnatal growth retardation resulting in height or weight below the 10th percentile. Characterized facial features include midface hypoplasia, micropthalmia, short palpebral fissures, ptosis, underdeveloped ears (railroad appearance), smooth philtrum, thin upper lip. CNS findings include microcephaly, intellectual impairment, cognitive impairment, developmental delay (global), and irritability in infancy. Skeletal abnormalities include clinodactyly of the fifth fingers, camptodactyly, and "hockey stick" palmar creases. Functional problems: Myopia, astigmatism, hearing loss. Cardiac defects are also common.
Teratogens: Agents that can cause congenital malformations in a developing embryo or fetus.

Dysmorphology Terms

Brachycephaly: Head shape shortened from front to back. Skull is rounder than normal.
Canthus: Lateral or medial angle of the eye, formed by the junction of the upper and lower eyelids.
Columella: Fleshy tissue of the nose that separates the nostrils.
Glabella: Bony midline prominence of the brows.
Nasal alae: Lateral flaring of the nostrils.
Nasolabial fold: Groove extending from the margin of the nasal alae to the lateral aspects of the lips.
Telorism: Pertaining to the spacing of the eyes.
- Ocular Hypertelorism: Increased distance between the pupils of two eyes.
- Ocular Hypotelorism: Decreased distance between the pupils of two eyes.
Palpebral Fissure: Shape of the eyes based on the outline of the eyelids.
Philtrum: Vertical groove in the midline of the face between the nose and the upper lip.
Plagiocephaly: Asymmetrical head shape in the sagittal or coronal planes. Can result from suture closure asymmetry or asymmetrical brain growth. Can also be positional.
Scaphocephaly: Head elongated from front to back. Most normal skulls are slightly scaphocephalic.
Synophrys: Eyebrows that meet in the midline.
Telecanthus: Widened space between the medial canthus (inner canthal distance).

Terms Pertaining to the Extremities

Brachydactyly: Condition of having short digits.
Camptodactyly: Digit bent or fixed in the direction of flexion. "Trigger finger" type appearance.
Clinodactyly: Digit is crooked and curves toward or away from adjacent digits.
Hypoplastic Nail: Unusually small nail on a digit.
Melia: Suffix meaning "limb."
- Amelia: Missing limb.
- Brachymelia: Shortened limb.
Oligodactyly: Deficiency in the number of digits.
Polydactyly: Having six or more digits on an extremity.
Syndactyly: Two or more digits at least partially fused.

Chromosomal Disorders

Trisomy 13 (Patau Syndrome): 47, XX +13 or 47, XY +13. Occurs 1:12,000 live births. Usually fatal in the first year of life.
- Key features: SGA, microcephalic, midline facial defects (cyclopia, cebocephaly, cleft lip and palate), sloping forehead, small and malformed ears, micro- or anopthalmia, polydactyly, clinodactyly, clubfeet or rocker-bottom feet, aplasia cutis congenita (punched out scalp lesion over right or left occiput).
- Other clinical manifestations: Scalp defects, micropthalmia, corneal abnormalities, cleft lip and palate, microcephaly, sloping forehead, capillary hemangiomas, deafness. Chest: Congenital heart disease (VSD, PDA, and ASD), thin posterior ribs. Extremities: Overlapping fingers and toes, polydactyly. General: SGA, severe developmental delays, prenatal and postnatal growth retardation, renal abnormalities.
Trisomy 18 (Edwards Syndrome): 47, XX +18 or 47, XY +18. The second most common autosomal trisomy. Occurs ~ 1:7,500 live births.
- Key features: 50% have renal anomalies (horseshoe kidney). Hypothyroidism is 5x more likely.
Trisomy 21 (Down’s Syndrome)
Klinefelter’s Syndrome (XXY)
Turner’s Syndrome (XO)
Cri Du Chat Syndrome: Deletion on short arm of chromosome 5. Larger deletion is associated with more severe expression. Characteristic "cat-like" cry during infancy due to tracheal hypoplasty.
- Key features: Low birth weight, postnatal failure to thrive, hypotonia, developmental delay, microcephaly, craniofacial dysmorphism (ocular hypertelorism, epicanthal folds, downward obliquity of the palpebral fissures, low-set malformed ears), clefts of the lip and palate, congenital heart disease.
Fragile X Syndrome (FRAX): Disorder caused by expansion of trinucleotide repeats. ~1:2000 children. The most common cause of inherited mental retardation. Genetic males are affected more severely than genetic females.
- Key features: Craniofacial findings (large head, prominent forehead, jaw, and ears), macro-orchidism (testicular volume twice normal in adulthood), connective tissue abnormalities, mitral valve prolapse, characteristic neurobehavioral profile (mental retardation, autism spectrum disorder, pervasive developmental disorder).

Teratogenic Disorders

~ 6.5 of all birth defects are attributed to teratogens, which are chemical, physical, or biological agents that have the potential to damage embryonic tissue.
Examples of teratogens: Prescription and nonprescription drugs, intrauterine infections, maternal diseases, environmental substances.

Fetal Alcohol Syndrome

10-20:1000 children. Most common teratogenic syndrome.
To cause "full-blown" fetal alcohol syndrome, pregnant women must drink at least 6oz alcohol each day during pregnancy.
Even one episode of consuming two alcoholic drinks during pregnancy may lead to loss of fetal brain cells and milder signs and symptoms.
- One drink = 12 oz of beer, 5 oz of wine, or 1.5 oz of "hard" liquor.
Key features: Prenatal and postnatal growth retardation. Characteristic Facial Features - midface hypoplasia, micropthalmia, short palpebral fissures, ptosis, underdeveloped ears, smooth philtrum, thin upper lip. CNS Findings - Microcephaly, intellectual impairment, cognitive impairment, developmental delay (global), irritability in infancy, hyperactivity. Skeletal abnormalities - clinodactyly of the fifth fingers, camptodactyly, "hockey stick" palmar creases. Functional Problems: Myopia, astigmatism, hearing loss. Cardiac Defects.

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Description

This quiz covers essential anatomical terms related to the face and head. Explore definitions and characteristics of various facial features, from the nasal structure to eye spacing. Test your knowledge on terms vital for understanding human anatomy and medical terminology.