Cartilage hair hypoplasia, metaphyseal chondrodysplasia type McKusick: Description of seven patients and review of the literature

We describe 7 cases of cartilage hair hypoplasia (CHH) with emphasis on the clinical and immunological aspects. The literature on CHH is reviewed and symptoms in 63 non-Amish cases are summarized. In this autosomal recessive disorder the immunodeficiency, hair abnormalities, and severity of skeletal involvement show extremely variable expressivity, between and within families. Two of the 3 sib-pairs among our cases demonstrate the great difference in expression within one family. At adult age roentgenological abnormalities can be very mild, or even absent. An impairment in cell- mediated immunity is present in all of our cases and seems a consistent manifestation in CHH; however, sometimes it is very subtle and without clinical symptoms.