"Brittle" Hair With Short Stature, Intellectual Impairment and Decreased Fertility: An Autosomal Recessive Syndrome in an Amish Kindred

Abstract

During a study of an Amish population of Northern Indiana, 25 individuals with a syndrome of brittle hair, short stature, and intellectual impairment were found in one large kindred. Observations in 20 of these affected individuals have shown that the short stature and intellectual impairment are relatively mild except in the propositus who also has a deletion of a portion of the long arm of chromosome 14. The hair in each affected individual has an abnormal appearance by light and scanning electron microscopy with an irregular grooved surface lacking in scales. Polarization microscopy of the hair revealed an alternating birefringent pattern. Neutron activation analysis of the hair of 11 affected individuals showed the sulfur content to average 2.51% by weight (approximately one half that of controls and nine obligate heterozygotes). This condition can be differentiated from Menkes' kinky-hair syndrome by the microscopic appearance of the hair, the normal copper and ceruloplasmin levels and the mode of inheritance. The syndrome being reported has similarities to and may be identical with a condition previously reported in two siblings by Pollitt et al. in 1968 and that reported in a 4-year-old girl by Brown et al. in 1970. The number of affected individuals and their distribution in this large kindred have provided evidence for the autosomal recessive inheritance of the condition and for its decreased fertility.