Genetic Diseases - Unit 2 Flashcards
Triploidy
69, XXX or XXY (caused by dispermy)
Tetraploidy
4n (caused by endomitosis)
Down Syndrome
Trisomy 21, due most commonly to nondisjunction. Characterized by midfacial hypoplasia, low ears, low muscle tone, etc. Potential heart and GI defects, eye/ear and endocrine problems, atlantoaxial subluxation, depression, alzheimer’s, autism.
Patau Syndrome
Trisomy 13
Edwards Syndrome
Trisomy 18
Klinefelter Syndrome
47, XXY (male with reduced secondary sex characteristics, gynocomastia; error in paternal meisos I)
Aneuploidy
Loss or gain of chromosome (most due to nondisjunction during maternal meiosis I)
47, XXY Syndrome
Due to error in paternal meiosis II, producing YY sperm
Turner Syndrome
45, XO (some females survive). Characterized by webbed neck, short stature, infertility.
Prader-Willi Syndrome
Imprinted regions on Chr 15. Deletion of paternal allele or uniparental disomy of maternal allele. Also, 15q interstitial duplication from mother or isochromosome.
Angelman’s Syndrome
Imprinted regions on Chr 15. Deletion of maternal allele. (There are four mechanisms: large deletion, mutation, paternal uniparental disomy, or imprinting defect.)
Chronic Myelogenous Luekemia (CML)
Translocation (9;22). Treated with Gleevec, a tyrosine kinase inhibitor.
Acute Promyeloid Leukemia (APML)
Translocation (15;17). Treated with retinoic acid.
Acute Lymphoblastic Leukemia
High hyperdiploidy (better outcomes than loss of tumor suppressor genes in hypodiploidy cancers)
Gaucher’s Disease
Autosomal recessive. Causes buildup of fatty substance called glucocerebroside in macrophages due to ineffective breakdown by glucocerebrosidase. Treated by enzyme replacement therapy.
