Week 1: Cyto, Aneuploidy, Deletions Flashcards
5 main features of T21
Hypotonia, ID, flat facial profile, CHD, GI anomalies
Most common genetic cause of T21
Nondisjunction
Mosacism is always a _____ event
Mitotic
RR for nondisjunction T21
1% OR maternal age risk
5 major features of T18
Hypertonia, clenched fist with overlapping 3rd and 4th finger, rocker-bottom feet, ID, hernia
RR for T18
Less than 1% (since most SAB)
5 major features of T13
(Midline) HPE, CL+P, polydactyly, omphalocele, ID+ seizures
RR for T13
Less than 1% (since most SAB)
5 major features of 22q11
Velopharngyeal incompetence, CHD, asymmetric crying facies, immunodeficiency, hypocalcemia
Is 22q usually de novo or inherited
de novo
5 major features of XXY
Hypogonadism, infertility, lower IQ than sibs, behaviour problems, gynecomastia
Treatment for XXY
Testosterone supplementation
5 major features of XO
Short stature, gonadal dysgenesis, webbed neck, CHD, transiet congenital lymphedema
Treatment for XO
Estrogen replacement therapy
Risk for 45, X/ 46, XY Mosaics
Gonadoblastoma
What is used to stop the cell cycle in metaphase when making a karyotype
Colchicine
Best uses for FISH
Partial/full aneuploidy–but you must known what you are looking for
Array CGH cannot detect
Balanced translocations, triploidy
SNP-array is useful for detecting:
Consanguinity (ROHs), triploidy, UPD
4 posible gametes for reciprocal translocation carrier
Normal, Balanced, Unbalanced (two forms)
3 major features of Cri du Chat
Cat-like cry, microcephaly, low birth weight