3: Prenatal screening/dx/tx Flashcards
sickle cell anemia
AR disease caused by a single point mutation in the gene for the beta chain in hemoglobin
tay-sachs symptoms
- loss of alertness and an excessive reaction to noise (hyperacusis).
- developmental delay and neurologic degeneration in intellectual and neurologic function. -Myoclonic and akinetic seizures can present 1 to 3 months later.
- -cherry-red spot: prominent red macular fovea centralis is contrasted by the pale retina.
- paralysis, blindness, and dementia, and typically die by age 4 years.
tay-sachs caused by ?
deficiency of hexosaminidase A (hex A), the enzyme responsible for the degradation of GM2 gangliosides
-leads to accumulation of gangliosides in lysosomes–>enlarged neurons with lipid filled lysosomes, cellular dysfunction and neuronal death`
first trimester screen
11 to 14 weeks
nuchal translucency, which is combined with pregnancy-associated plasma protein A (PAPP-A) and β-hCG
second-trimester screen
15-20 weeks
quadruple (quad) screen and includes MSAFP, estriol, β-hCG, and inhibin
Down syndrome associated features
short stature, classic facies, developmental delay, and mental retardation with IQs ranging from 40-90. cardiac defects, duodenal atresia or stenosis, and short limbs.
Trisomy 18
Edward syndrome
clenched fists, overlapping digits, and rocker bottom feet. Cardiac defects: (VSD), ToF, omphalocele, congenital diaphragmatic hernia, neural tube defects, and choroid plexus cysts (seen on US)
Trisomy 13
Patau syndrome
holoprosencephaly, cleft lip and palate, cystic hygroma, single nostril or absent nose, omphalocele, cardiac anomalies including hypoplastic left heart, and limb anomalies including clubfoot and clubhand, polydactyly, and overlapping fingers
45,X
Turner syndrome, or monosomy X
short stature.
-primary amenorrhea, sexual infantilism, webbed neck, low-set ears, low posterior hairline, epicanthal folds, wide carrying angle of the arms, shield-like chest, wide-set nipples, short fourth metacarpal, renal anomalies, lymphedema of the extremities at birth, and CV anomalies: coarctation of the aorta. seen on U/S: cystic hygroma
47,XXY
Klinefelter syndrome
- small, firm testes and hyalinization of the seminiferous tubules.
- infertility, gynecomastia, mental retardation, and elevated gonadotropin levels due to the decreased levels of circulating androgens.
endoderm
GI and respiratory systems
mesoderm
CV, musculoskeletal, GU
ectoderm
nervous system, skin, and many sensory organs (e.g., hair, eyes, nose, and ears)
most NTDs result from
defective closure by week 4
spina bifida dx findings
ultrasound findings of the “lemon” sign (concave frontal bones), and the “banana” sign (a cerebellum that is pulled caudally and flattened)
elevated amniotic fluid α-fetoprotein (AFP) that crosses into the maternal serum (MSAFP)
