Two sibs with brachyolmia type Hobaek: five year follow-up through puberty.
A brother and a sister affected with brachyolmia (short trunk) are reported. Their radiological findings are compatible with brachyolmia, Hobaek type, which is characterized by platyspondyly, horizontal acetabular roof, short femoral neck, and vertical "mixed lucent and dense" striation pattern in the metaphyses of large long bones. Despite normal birth weight and length, the platyspondyly is present at infancy, but clinically the condition may not be noticeable until late childhood or early puberty, when stunted growth becomes apparent. Beyond puberty, the patients are short in stature, mainly due to a short trunk with decrease upper and lower body segment ratio. Brachyolmia type Hobaek is a relatively benign condition. It may cause a mild and nonspecific backache that usually is not debilitating. The inheritance mode is apparently autosomal recessive.