GeneticDisorders-III Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Question | Answer |
multifactorial inheritance | determined by 2 or more genes, conditioned by non-genetic influences; examples: cleft lip or palate, congenital heart dz, CAD, HTN, gout, DM, pyloric stenosis |
advantages of FISH over cytogenetics | able to detect submicroscopic aberrations, can use non-dividing (in interphase) cells for analysis |
Down syndrome | trisomy 21, most common constitutional chr abnormality, 1/700 births, associated with advanced maternal age |
physical features of Down syndrom | prominent epicanthal folds, low-set ears, macroglossia, MR, abundant neck skin, duodenal atresia ("double bubble"), congenital heart defects, HYPOtonicity, predisposition to leukemia |
del(22q11.2) or DiGeorge/velocardiofacial syndrome | microdeletion syndrome causing nasal-sounding speech, congenital heart defects, hypocalcemia and T-cell immunodeficiency b/c 4th pharyngeal pouch is absent = thymic and parathyroid a/hypoplasia |
trisomy 18 (Edwards syndrome) | lethal trisomy, 1/8000 births, clenched fists/HYPERtonicity can be seen on son, clinodactyly, intrauterine growth defects, congenital heart problems |
trisomy 13 (Patau syndrome) | lethal trisomy, midline defects = cleft lip and palate, holoprosencephaly, fusion of frontal lobes, agenesis of cerebellar vermis |
term for inactivation of one X chr | lyonization |
heteropyknosis of one X chr results in? | Barr body, occurs after 16th day of life |
higher # of X chr can be associated with greater likelihood of phenotypic effect and MR | XXY, XXXY |
Turner syndrome | 45XO, 1/2-3,000 births; phenotype: short stature, coarctation of aorta, webbed neck, streak ovaries = menopause before menarche, widely-spaced nipples. usually short females without mental compromise |
Klinefelter syndrome | XXY or XXXY, 1/500 births, more common than Down syndrome, phenotype: hypogonadism, pear-shaped figure due to overproduction of androgens that are converted peripherally to estrogen, long legs, infertility, no MR |
genetic sex | determined by presence/absence of sex-determining region of the Y chr (SRY gene) |
gonadal sex | histological appearance of gonads |
ductal sex | presence of Mullerian or Wolffian ducts |
genital or phenotypic sex | appearance of external genitalia |
true hemaphrodite | have both ovarian and testicular tissue, XX- or XY- cell lines |
female hemaphrodite | XX with ovaries but male external genitalia b/c they weren't able to respond to estrogens in utero. CAH - defect in enzyme resulting in overproduction of androgens |
male hemaphrodite | Y chr and testes but external genitalia are ambiguous or overtly female, results from androgen insensitivity, AR is defective so not able to respond even to nl levels of testosterone/DHT |
Fragile X syndrome | X-linked disorder, 200 or more CGG repeats in noncoding region of FMR-1 gene; phenotype: long face and mandible, large and everted ears, macro-orchidism, 2nd most common cause of MR |
inheritance pattern of fragile X syndrome | X-linked with differences; female carriers show manifestation usually, worsens with each generation (Sherman paradox) so grandfather was prob not affected, mother was mildly, grandson has full blown dz |
example of trinucleotide repeat disorder | affects coding region - Huntington dz |
mitochondrial disorder | COMPLETE maternal transmission; organs that use oxidative phosphorylation are affected, heteroplasmy, threshold effect. ex: Leber hereditary optic neuropathy |
heteroplasmy | tissues or entire organism harbor both mutant and WT-mitochondrial DNA |
Prader-Willi | disorder of genomic imprinting & microdeletion syndrome; mother has imprinted (silenced by methylation) chr 15 so when dad passes down chr 15 with microdeletion in that region + mom's silenced chr 15, dz develops |
Angelman syndrome | disorder of genomic imprinting & microdeletion syndrome; father has imprinted (silenced by methylation) chr 15 so when mom passes down chr 15 with microdeletion in that region + dad's silenced chr 15, dz develops |
indications for prenatal genetic testing | advanced maternal age, parent has chr aberration, prev child with one, sono-detected abnormalities, parent is carrier of an X-linked disorder |
indications for postnatal genetic testing | multiple congenital anomalies, MR/developmental delay, suspected autosomal numerical or structural or sex chr aberration, suspected fragile X, infertility, multiple spontaneous ab or FMHx of miscarriages |
Created by:
sirprakes
Popular Genetics sets