Chromosomal Genetic Disorders PPT PDF

CHROMOSOMAL GENETIC DISORDERS BRENDALE ANNE A. SOLIS/DCGNHS Meiosis may not always proceed normally. Problems during meiosis sometimes happen and cause great harm during embryonic development. Example: ✓Miscarriages, genetic errors, and birth defects may occur.  CHROMOSOMAL GENETIC DISO...

CHROMOSOMAL GENETIC DISORDERS BRENDALE ANNE A. SOLIS/DCGNHS Meiosis may not always proceed normally. Problems during meiosis sometimes happen and cause great harm during embryonic development. Example: ✓Miscarriages, genetic errors, and birth defects may occur.  CHROMOSOMAL GENETIC DISORDERS Chromosomal Genetic disorders occur when a mutation affects your genes or when you have the wrong amount of genetic material. *Mutation - a harmful change to a gene. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Chemicals - like those inhaled while smoking, radiation such as X-rays, and ultraviolet light.  Types of mutations Point mutation Substitution Deletion Insertion https://evolution.berkeley.edu/dna-and-mutations/types-of-mutations/  Substitution One base is inserted incorrectly during replication, replacing the pair at the appropriate location on the complementary strand. Sickle-cell anemia https://www.mayoclinic.org/content/dam/media/en/images/2023/02/09/sickle-cell-anemia.jpg https://www.yourgenome.org/facts/what-types-of-mutation-are-there/  Insertion In replicating DNA, one or more additional nucleotides are added. https://www.yourgenome.org/facts/what-types-of-mutation-are-there/  Deletion During replication, one or more nucleotides may be “skipped” or removed. Cystic fibrosis  Chromosomal Mutation Deletion When a chromosome segment is lost, all the genes in that segment are also gone. https://medlineplus.gov/images/PX00006K_PRESENTATION.jpeg  Duplication A chromosomal segment is repeated, increasing the concentration of the genes in that area. Cancers VIDEO PRESENTATION VIDEO NUMBER 3 Turner Syndrome  Vocabulary 1. Meiotic nondisjunction is the failure of homologous chromosomes to segregate properly to opposite poles during meiosis resulting in the production of gametes that have an improper chromosome complement. 2. Aneuploidy -extra or missing chromosome – a common cause of genetic disorders (birth defects). Example: A. There are missing pieces of chromosomes and/or genetic material. Some may be small and difficult to detect. 1.TRISOMY B. Absence of one of the 2.MONOSOMY chromosomes. 3.DELETIONS C. Presence of an extra chromosome. 4.TRANSLOCATIONS D. Pieces of chromosomes break off and reattach to another chromosome. Based on data curated by Orphanet and Online Mendelian Inheritance in Man (OMIM), an average of about 260–280 rare genetic diseases are discovered per year. TRISOMY 21/DOWN SYNDROME Trisomy 21/Down syndrome is a disorder caused by the malfunction of the cell during cell division that results in an extra copy of chromosome 21. TRISOMY 21 OR DOWN SYNDROME MALFUNCTION: There is an Extra copy of chromosome 21 instead of the normal 2 copies. Normal chromosome  SIGNS AND SYMPTOMS ❑Distinctive facial features - slanted eyes, a flat nasal bridge, and a small mouth. ❑Flexible joints and weak, floppy muscles. ❑Inwardly curved little finger. (Clinodactyly) ❑Wide space between the great and second toe ❑ Short stature: Individuals with Down syndrome are often shorter than average. ❑ Small hands and feet: The extremities may be proportionally smaller. ❑ A single, deep crease across the palm of the https://s3.amazonaws.com/HMP/c360/imported/transfer/Screen_S hot_2015-10-13_at_2.46.02_PM.png hand (known as a simian crease).  CRI-DU-CHAT SYNDROME/ CAT’S CRY SYNDROME Cri-du-chat or cat's cry syndrome, also known as 5p- (5p minus) syndrome, is a chromosomal condition that results when a piece of chromosome 5 is missing. Infants with this condition often have a high-pitched cry that sounds like that of a cat. NORMAL CHROMOSOME CRI-DU-CHAT/CAT’S CRY SYNDROME Malfunction: Deletion of the end of the short (p) arm of chromosome 5.  SIGNS AND SYMPTOMS ❑High-pitched cat-like cry ❑Mental retardation ❑Delayed development ❑Distinctive facial features: Small head size (microcephaly) and widely-spaced eyes (hypertelorism) ❑ Low birth weight and weak muscle tone (hypotonia) in infancy.  TURNER SYNDROME Turner syndrome is a genetic condition affecting women, in which 1 X chromosome is partly or completely missing. Turner syndrome is caused by the loss of the second sex chromosome. TURNER SYNDROME VS. NORMAL FEMALE CHROMOSOME  SIGNS AND SYMPTOMS ❑Short Stature: Girls with Turner syndrome are typically shorter than average. ❑Have underdeveloped or non- functional ovaries, which leads to infertility. They do not https://encrypted- undergo puberty without tbn0.gstatic.com/images?q=tbn:ANd9GcQqcVnV9LKnVSc2V24BVVPX3aw hUG7yYjdU7ISFjzJrMSAtQTeSxQVjibaSrpf90Ba1000&usqp=CAU hormone replacement therapy.  SIGNS AND SYMPTOMS ❑ Webbed neck: Some girls with Turner syndrome have a "webbed" appearance to their neck, caused by excess skin. ❑ Low-set ears. ❑ A broad chest with widely spaced nipples. ❑ A high-arched palate. ❑ Puffiness of the hands and feet, especially at birth.  Low-set ears High-arched palate https://encrypted- tbn0.gstatic.com/images?q=tbn:ANd9GcRbSBGGhl7hJwTV8_7 EB0-GHMn9tvtn9QszBw&usqp=CAU https://dentagama.com/img/070619062316SoftandHardPalat e.jpg  TRISOMY 18/EDWARD’S SYNDROME Trisomy 18 is also called as Edward’s syndrome because it was first described by Doctor Edward. Most cases of Trisomy 18 result from having three copies of chromosome 18 instead of the usual two copies. Malfunction: Three copies of chromosome 18 instead of the usual two copies.  SIGNS AND SYMPTOMS ❑ Small, abnormally shaped head (microcephaly). ❑ Prominent occiput (back of the head). ❑ Low-set ears. ❑ Small mouth and jaw. ❑ Cleft lip and palate or other palate abnormalities. ❑ Clenched fists with overlapping fingers. ❑ Micrognathia (small chin). https://journals.healio.com/cms/asset/9e561cfe-2f46-4768-8a28-4c8990b3dccb/10.3928_00904481-20070501-08-fig1.jpg  Clenched fists with overlapping Micrognathia (small chin) fingers https://www.researchgate.net/publication/225644327/figure/fig1/AS:370973489549313@1465458381015/Frontal-view-of- https://www.researchgate.net/publication/269725311/figure/fig2/AS:270235248885782@1441440512837/Clenched-fists- face-showing-severe-micrognathia.png adducted-thumbs-bilateral-overlapping-2nd-finger-over-thumbs-bilateral.png  TRISOMY 13/PATAU SYNDROME Trisomy 13 is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Trisomy 13/Patau syndrome results from having three copies of chromosome 13 instead of the usual two copies. TRISOMY 13/PATAU SYNDROME CHROMOSOME Malfunction: There are three copies of chromosome 13 instead of the usual two copies.  SIGNS AND SYMPTOMS ❑ Babies with Patau's syndrome can have a wide range of health problems. Their growth in the womb is often restricted, resulting in low birth weight, and 8 out of 10 will be born with severe heart defects. ❑ The brain often does not divide into 2 halves. This affects facial features and cause defects such as: ❑ Cleft lip and palate ❑ Abnormally small eye or eyes (microphthalmia) ❑ Absence of 1 or both eyes (anophthalmia) ❑ Reduced distance between the eyes (hypotelorism) ❑ Problems with the development of the nasal passages.  Klinefelter Syndrome Klinefelter syndrome is a common genetic condition where a male is born with an extra X chromosome. Typically, a male has one X and one Y chromosome.  SIGNS AND SYMPTOMS ❑ Small testes ❑Gynecomastia: The development of breast tissue, which can vary in severity. ❑ Tall stature: Affected https://i0.wp.com/post.medicalnewstoday.com/wpcontent/uploads/sites/3/2021/12/1_Adolescent_w h_Gynecomastia.jpg?w=1155 individuals may be taller than average. ❑Reduced body and facial hair growth. ❑ Long arms and legs ❑ A reduced muscle mass. https://d3i71xaburhd42.cloudfront.net/f85f34476ddf07ee0787c1b9b779c7994ef4cf09/2-Figure1-1.png  DOWN SYNDROME Today, the average life expectancy of a person with Down syndrome is almost 60 years and continuing to rise, thanks to advancements in treatment. Over 6,000 babies are born with Down syndrome in the United States each year. The estimated Down syndrome prevalence is between 1 in 1,000 to 1 in 1,100 live births worldwide, according to the World Health Organization. https://www.crossrivertherapy.com/down-syndrome-life-expectancy  Women who have had one child with Down syndrome have an increased chance of having another child with the condition. The prevalence of Down syndrome increases as the mother’s age increases.  TRISOMY 18 Trisomy 18 occurs at a rate of 1 in 2000-6000 live births. It is somewhat more common as the mother ages but can occur randomly in parents of any age. Most babies affected are girls. There is no known cause of Trisomy 18. Studies have shown that only 50% of babies who are carried to term will be born alive. The median of survival among live births has varied between 2.5 and 14.5 days. About 90% - 95% of babies do not survive beyond the first year and many live only a few days. Minnesota Department of Health. (Mar 27, 2023) https://www.health.state.mn.us › diseases › trisomy1  TRISOMY 13 Trisomy 13 occurs in 1 of 10,000-16,000 births and the incidence increases with increased maternal age. The risk of recurrence in future pregnancies is 1%. Most cases are not inherited and result from random formation of eggs and sperm in healthy parents. Using data from Minnesota births between 2014-2018, we found 13 babies were born with Trisomy 13, resulting in a rate of