GROWTH IN CARTILAGE-HAIR HYPOPLASIA

Cartilage-hair hypoplasia is an osteochondrodysplasia with short-limbed short stature. The cartilage-hair hypoplasia gene is exceptionally prevalent in Finland; more than 100 patients have been identified. We have analyzed the growth of 100 Finnish patients and present cartilage-hair hypoplasia-specific growth charts of height and weight for height. The disproportions were analyzed by sitting height, subischial leg height, sitting height:height ratio, and span-height difference. The stature was short at birth with a mean relative length of -3.0 SD. The median adult height was 131.1 cm (-7.9 SD, range 110.7 to 149.0 cm) for 15 males and 122.5 cm (-7.9 SD, range 103.7 to 137.4 cm) for 20 females. The progression of the growth failure was partly explained by weakness or absence of pubertal growth spurt. Weight for height was above normal median in childhood and increased further at puberty. Most of the adults were overweight. The adults' mean relative head circumference was -0.9 SD. Growth was disturbed both in the limbs and in the spine, more severely in the limbs. Adult height showed no correlation with the midparent height. The charts are useful for assessment of growth, prediction of adult height, detection of superimposed disorders, and evaluation of growth-accelerating therapy.