Lecture 20 Flashcards
(14 cards)
The most common trisomies observed in live births involve chromosomes ____, ____, and ____ (in decreasing order of frequency.)
21
18
13
____ _____ paint can be used to uncover complex chromosomal rearrangements, especially in cancer cells where complex mutations may have occurred.
Whole Chromosome paint
____ _____ _____ (CGH) is now being used more so than karyotyping, because the former can better detect subtle chromosomal deletions and duplications. It compares chromosomes from a normal (control) to the patient.
Comparative Genomic Hybridization
Are Robertsonian translocations seen more so in offspring of younger or older mothers?
Younger
Trisomy ____ is cahracterized by bird-like facies, growth retardation, rocker-bottom feet, and HIGH muscle tone (hypertonicity).
18
Trisomy _____ is characterized by polydactyly, sloping forehead, micro-ophthalmia, holoprosencephaly, and oro-facial clefts.
13
Wolf-Hirschhorn syndrome is caused by a ____ of the p-arm on chromosome ____. Patients have characteristic helmet noses and highly arched eyebrows.
Deletion
4
DiGeorge syndrome arises from a 22q____ deletion. Patients exhibit a long, narrow face, _____ heart defects, ______ (calcium level due to issues with parathyroid), and immunodeficiency.
22q11.2
Conotruncal heart defects
Hypocalcemia
Sex chromosome aneuploidies are NOT associated with ______ disabilities, though they may exhibit less severe learning disabilities.
Intellectual
_____ syndrome results from a 45,X genotype or mossaicism with 45,X in some of the cells (one of the X chromosomes is missing, and it’s thought to be most commonly a result of a sperm without a sex chromosome fertilizing an egg with an X.) About 20% of these patients have other X chromosome abnormalities. Patients exhibit a _____ neck and infertility due to _____ failure.
Turner Syndrome
Webbed
Ovarian failure
Triple X syndrome patients don’t really show any physical features, have normal fertility, but may present with mild _____ disabilities and are at increased risk for _____ disorders.
Learning disabilities
Psychiatric disorders
_______ syndrome arises from nondisjunction and a resultant 47,__ __ __ genotype. These are male patients that show occasional ______ (large breasts, and thus increased risk of breast cancer), small testes, and infertility.
Kleinfelter’s
47,XXY
Gynecomastia
47,XYY results from a nondisjunction event in _____ cells. Do these males have normal or abnormal fertility?
Normal
In the case of a female offspring from a parent with an X:Autosome balanced translocation, does the offspring’s cells preferentially inactivate the normal or derivative X chromosome?
Normal
