Table 2.

Features of Microcephalic Osteodysplastic Primordial Dwarfism Type II

Feature% of Persons
w/Feature		Comment
Extreme pre- & postnatal growth restriction~100%IUGR, severe short stature
Microcephaly~100%
Skeletal dysplasia~100%Can develop hip deformity &/or scoliosis in addition to osteochondrodysplasia. Dysplasia may be difficult to recognize in newborn period.
Small, loosely rooted teeth~100%Frequency not definitively evaluated in large studies, but typically secondary teeth are more affected than primary teeth.
HematologicAnemia>75%Asymptomatic
Thrombocytosis>75%Asymptomatic
CerebrovascularAneurysms~50%Risk appears to be lifelong.
Moyamoya vasculopathy~50%Risk mainly in younger ages, starting in utero
Aneurysms & moyamoya disease36%
CardiovascularHypertension43%Median age 13 yrs
Hypercholesterolemia>32%Median age 18 yrs
Cardiac malformations28%ASD, VSD, PFO
Coronary artery disease w/premature MIs17%Median age of MI 24 yrs
RenalChronic kidney disease32%Renal transplantation documented in 2 persons
Accessory renal arteries15%All known affected persons have been male.
Renal vascular disease4%Renal artery stenosis, aneurysm
GenitalCryptorchidism / retractile testes44% of males
Hypospadias8% of males
EndocrineInsulin resistance &/or diabetes mellitus>38%Median age 11 yrs
Cognitive abilityBorderline/low-normal intellectual functionMostMore impairment in those who have had strokes
ADHDMostNot yet definitively evaluated in large studies

ADHD = attention-deficit/hyperactivity disorder; ASD = atrial septal defect; IUGR = intrauterine growth restriction; MI = myocardial infarction; PFO = patent foramen ovale; VSD = ventricular septal defect

From: Microcephalic Osteodysplastic Primordial Dwarfism Type II

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