Overgrowth syndromes Flashcards
what is a general way to think about overgrowth syndromes?
the body is large relative to what is expected
what are general trends seen in overgrowth syndromes?
weight is increased as much as length
condition is usually associated with various other anomalies
some degree of cognitive deficiency is often present
neoplasia occur at a higher rate than expected
familal macrocephaly, hemihyperplasia, KLippel-Trenaunay-Weber syndrome, Maffuci syndrome, NF, and Proteus syndrome are all examples of:
regional overgrowth syndromes
what is hemihyperplasia? is it sporadic? and preponderances?
abn cell proliferation restricted to one or more regions of body - asymmetric growth
mostly sporadic other than in NF and BWS
2:1 right sided and 2:1 female
how does proteus syndrome typically present? what gene is implicated? how penetrant? is it variable?
6-18mo w/ asymmetric growth most commonly in feet and hands
radiography often show irregular calcified overgrowth of bones
ATK1
> 90% have features
highly variable presentation
what is a common cause of generalized overgrowth (>2 SD of birth weight for GA)?
diabetic macrosomia
reflects hyperglycemia an hyperinsulinemia
what are some clinical features of BWS?
abdominal wall defects, neonatal hypoglycemia, macrosomia, macroglossia, hemihyperplasia, enlarged kidneys, renal abn, ear creases/pits
advanced bone age (most pronounced dur first 4y and rarely persists until puberty)
what growth trends are seen in BWS?
> 95%ile avg birth weight in males and parallels normal curve @ 95th%ilt through adolesence
75th%ile ave birth weight for females and increases to 95th%ile by 18mo, >9y mean weight remains 75-95th%ile
what neoplasm are children with BWS at risk for? surveillance?
Wilms tumors (96% by 8y)
abdominal U/S every 3mo
what are the various etiologies of BWS?
paternal UPD (10-20%) MZ twins (<1%) IGF2 loss to imprinting (50-60%) -- paternally expressed others
how should we order genetic testing for children with suspected BWS?
chromosome studies (all) -> CMA -> single gene -> methylations
what are some prenatal concerns with BWS?
premature (50%), polyhydramnios (50%), fetal macrosomia (90%), enlarged placenta, long umbilical cords, 20% perinatal mortality rate
sotos syndrome is characterized by: _______. other features? etiology/inheirtance?
prenatal onset of excessive size, advanced bone age, large hands and feet
prominent forehead, large circumference, DD (perhaps abn corpus callosum), poor coordination, etc.
most cases sporadic, some AD, mutations in NSD-1
what are some features of Simpson-GOlabi-Behmel syndrome? inheritance?
high birthweight, usually advanced bone age, large head at birth and in childhood, excessive adult weight, hypertelorism, sometimes CL/P
XL-recessive
what causes Simpson-Golabi-Behmel syndrome?
mutations/microdeletions of GPC-2 (Xp26)
