Short Stature with Increased Bone Density

Pycnodysostosis. It is an autosomal recessive disease associated with short stature, fractures, large head with frontal and parietal bossing, open anterior fontanelle and cranial sutures, obtuse mandibular angle, prominent eyes with bluish sclera, underdeveloped facial bones, persistence of deciduous teeth into adulthood often with caries, short, broad hands and feet with dystrophic nails and trunk deformities such as kyphosis, scoliosis, increased lumbar lordosis, and narrow chest. {1} Raised plasma calcitonin concentrations have been reported. {2} A generalized increase in bone density is seen on radiographs, but medullary canals are evident. The skull shows open anterior fontanelle and sutures with small facial bones, non-pneumatised paranasal sinuses and a flattened mandibular angle. Terminal phalanges in the hand are partially or totally aplastic with loss of ungual tufts. The deficiency of growth hormone is due to hypoplasia of pituitary gland caused by the compression of gland by the thickening of sella turcica. Several mutations have been found in the gene encoding cathepsin K, a cysteine protease that is highly expressed in osteoclasts. Dynamic study of tetracycline uptake reveals slowing down of bone resorption and formation. {3} Features which differentiate osteopetrosis from pycnodysostosis are normal stature, cranial nerve compression, non-differentiation of cortex from medulla in long bones, more severe modeling defect and an appearance of striations near the metaphyseal ends of long bones. {4}

Last Updated: August 2012 Vol 9 Issue 7 Art # 51

References :

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