Congenital Anatomic Defects Quiz
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Congenital Anatomic Defects Quiz

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anatomic defects that are mostly present at birth and some may not be clinically apparent until years later

Congenital anomalies

What year of birth is the most common cause of mortality of congenital anomalies?

First year

Refers to the process of organ and tissue development

Morphogenesis

Morphogenesis can be impaired by a variety of what errors?

<p>Malformations, Disruptions, Deformations, Sequence, Malformation syndrome</p> Signup and view all the answers

  • represent PRIMARY errors of morphogenesis
  • involves an INTRINSICALLY abnormal developmental process

<p>Malformations</p> Signup and view all the answers

Malformations can be a result of

<p>Single gene or chromosomal defect but are more commonly multifactorial in origin</p> Signup and view all the answers

one or more extra digits

<p>Polydactyly</p> Signup and view all the answers

fusion of digits

<p>Syndactyly</p> Signup and view all the answers

Cleft lip is what malformation syndrome

<p>Trisomy 13</p> Signup and view all the answers

severe and essentially lethal malformation, wherein the midface structures are fused or ill-formed; in almost all cases, this degree of external dysmorphogenesis is associated with severe internal anomalies such as maldevelopment of the brain and cardiac defects

<p>Stillbirth</p> Signup and view all the answers

SECONDARY destruction of an organ or body region that was previously normal in development and arise from an EXTRINSIC disturbance in morphogenesis and may be caused by a variety of environmental agents. NOT HERITABLE

<p>Disruptions</p> Signup and view all the answers

  • classic example of disruption
  • rupture of amnion with resultant formation of “bands” that encircle, compress, or attach to parts of the developing fetus

<p>Amniotic bands</p> Signup and view all the answers

  • also arise from an extrinsic disturbance in morphogenesis
  • involve localized or generalized compression of the growing fetus by abnormal biomechanical forces

<p>Deformations</p> Signup and view all the answers

  • serve as the most common underlying factor of deformations
  • between the 35th-36th week of gestation, rapid increase in the size of the fetus outpaces the growth of the uterus

<p>Uterine constraint</p> Signup and view all the answers

Maternal factors that increase the likelihood of excessive compression

<p>First pregnancy, small uterus, malformed (bicornuate) uterus, leiomyomas</p> Signup and view all the answers

Fetal or placental factors that increase the likelihood of excessive compression

<p>Oligohydramnios, multiple fetuses, abnormal fetal presentation</p> Signup and view all the answers

cascade of anomalies triggered by 1 initiating aberration, may be explained by a single localized aberration in organogenesis (malformation, disruption, deformation) → cause secondary effects in other organs

<p>Sequence</p> Signup and view all the answers

chronic leakage of amniotic fluid d/t rupture of amnion -uteroplacental insufficiency d/t maternal hypertension or severe toxemia renal agenesis

<p>Oligohydramnios</p> Signup and view all the answers

Oligohydramnios

<p>o flattened facies o positional abnormalities of hands and feet o breech presentation; dislocation of hips o hypoplastic lungs → usual cause of fetal demise o amnion nodosum (nodules in the amnion)</p> Signup and view all the answers

  • constellation of congenital anomalies that cannot be explained on the basis of a single, localized, initiating defect
  • most often caused by a single etiologic agent (e.g., viral infection, chromosomal abnormality) which simultaneously affects several tissues

<p>Malformation syndrome</p> Signup and view all the answers

complete absence of an organ and its associated primordium

<p>Agenesis</p> Signup and view all the answers

absence of an organ that occurs d/t failure of growth of the existing primordium

<p>Aplasia</p> Signup and view all the answers

absence of an opening of a hollow visceral organ (e.g., trachea, intestine)

<p>Atresia</p> Signup and view all the answers

incomplete development or decreased size of an organ with decreased number of cells

<p>Hypoplasia</p> Signup and view all the answers

enlargement of an organ d/t increased number of cells

<p>Hyperplasia</p> Signup and view all the answers

abnormal organization of cells

<p>Dysplasia</p> Signup and view all the answers

Arise from gametogenesis (not familial) o Examples:

  • Down Syndrome and other trisomies
  • Turner Syndrome
  • Klinefelter syndrome

<p>Chromosomal aberrations (10-15%)</p> Signup and view all the answers

o underlie major malformations o characterized by mendelian inheritance

<p>Single-gene mutations (2-10%)</p> Signup and view all the answers

  • most common form of short limb dwarfism
  • gain-of-function mutations in fibroblast growth factor receptor 3 (which is a negative regulator of bone growth)

<p>Achondroplasia</p> Signup and view all the answers

Holoprosencephaly

<ul> <li>most common developmental defect of the forebrain and midface in humans</li> <li>loss-of function mutations in Hedgehog signaling pathway (which plays a critical role in the morphogenesis of the said structures)</li> </ul> Signup and view all the answers

  • most common form of short limb dwarfism
  • gain-of-function mutations in fibroblast growth factor receptor 3 (which is a negative regulator of bone growth)

<p>Achondroplasia</p> Signup and view all the answers

Single gene mutations (2-10%)

<p>Holoprosencephaly, Achondroplasia</p> Signup and view all the answers

Maternal/placental infections

<p>Rubella, Cytomegalovirus, Herpes simplex, varicella-zoster, influenza, mumps, HIV, and enterovirus</p> Signup and view all the answers

  • infection extends from shortly before conception to the 16th week of gestation
  • Hazard greater in the FIRST 8 weeks than in the second 8 weeks

<p>Rubella</p> Signup and view all the answers

cataracts, heart defects, deafness, mental retardation

<p>Congenital rubella syndrome</p> Signup and view all the answers

CNS involvement, metal retardation, microcephaly, deafness, hepatosplenomegaly

<p>Cytomegalovirus</p> Signup and view all the answers

  • most common fetal viral infection
  • highest at risk period: 2nd trimester of pregnancy

<p>Cytomegalovirus</p> Signup and view all the answers

Maternal diseases states (6-8%)

<p>diabetes, phenylketonuria, endocrinopathies</p> Signup and view all the answers

  • cause maternal hyperglycemia-induced fetal hyperinsulinemia or diabetic embryopathy
  • results in fetal macrosomia (organomegaly + increased body fat and muscle mass)

<p>Diabetes mellitus</p> Signup and view all the answers

  • used as a tranquilizer
  • causes 50-80% of limb abnormalities in exposed fetus

<p>Thalidomide</p> Signup and view all the answers

Mode of action of thalidomide

<p>downregulation of WNT signaling pathway through the upregulation of endogenous WNT repressors</p> Signup and view all the answers

Most widely used teratogen and cause fetal alcohol syndrome

<p>Alcohol</p> Signup and view all the answers

What pathways does alcohol disrupt?

<p>Retinoic acid signaling pathway and Hedgehog signaling pathway</p> Signup and view all the answers

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