Karyotype Abnormalities & Aneuploidy Flashcards
Present in females
Symptoms - short stature, delayed puberty, infertility, learning disabilities, congenital heart defects
Turner’s Syndrome (Monosomy X)
X0
affects males
Female pubertal characteristics (small breasts, high voice and lower muscle tone)
Klinefelter’s Syndrome
XXY,
Can be lethal; most common chromosomal abnormality
Specific features - bracycephaly (flattened back of head), no nose bridge, enlarged tongue, intellectual disability, dementia in 50s
Hypotonia
Higher risk of leukemia
Down Syndrome (trisomy 21)
Affects females
Unbalanced Robertsonian translocation
Symptoms - onophthalmia (cleft lip),absent optic nerve (eye problems), polydactyl (extra digits), microcephaly (small head), omphalocoele (inflated umbilical cord), malrotation
Patau Syndrome (Trisomy 13) 47, XX, +13
lethal
Monosomy 21
45, X0, +21
Down Syndrome Acronym
(D)uodenal atresia
(O)
Lo(W) IQ
(N)eoplasia; Non-disjunction
2nd most common chromosomal abnormality,
Makes up 90% of cytogenetic causes
Features - clenched hands, rocker-bottom feet, prominent occipital (pointy back of head), small for gestational age, malrotation
Edward Syndrome (Trisomy 18)
Trisomy 18, key feature
Bilateral Foot deformity
Trisomy 13, feature
Cleft lip/ palate, microophthalmia (small eyes),
Inflated umbilical cord
Down Syndrome
1st and 2nd Causes and Physical Features
- Most commonly caused by nondisjunction leading to trisomy
- Robertsonian Translocation btw. chromosome 14 and 21
Bracycephaly, flappy skins at the back of the head, enlarged tongue, upslanted palpebral eye lids
Prader-Willi Syndrome
Pathogenesis and features
Paternal deletion; maternal (uniparental disomy)
(P for Prader, “Big” Papa Prader)
Hypoplasia, big appetite, small genitals, “obesity”
Angelman Syndrome
pathogenesis and features
Maternal deletion; paternal imprint
(Mom is an Angel)
More severe condition, nonverbal, always smiling
