Patterns of inheritance of constitutional delay of growth and puberty in families of adolescent girls and boys referred to specialist pediatric care.

Abstract

Constitutional delay of growth and puberty (CDGP), more commonly observed in boys than girls, often has a familial background. We characterized the occurrence of CDGP in relatives of CDGP patients to elucidate the mechanisms influencing timing of puberty. We identified 492 subjects with CDGP from hospital records of two pediatric clinics in Finland; 95 male and 29 female subjects and their first-degree relatives participated. In family members, CDGP was defined by use of growth charts (growth spurt taking place 2 sd beyond the mean). One third of the families was expanded to include also second-degree relatives with an interview-based assessment of pubertal timing. Of males, 80%, and of female probands, 75% had first-degree relatives with CDGP. Of all probands, 45% had one parent (unilineal families) and 32% had two parents affected. In 2% of the families, only siblings were affected. The prevalence of CDGP in male first-degree relatives was only slightly higher than in female relatives: 79 of 148 (53%) vs. 64 of 164 (39%), respectively (P=0.01); male to female ratio was 1.2:1. In 74% of extended unilineal pedigrees (17 of 23), the inheritance pattern of CDGP was consistent with autosomal dominant inheritance. CDGP clusters in families. Although its inheritance likely is complex, some predisposing genetic factors may have a dominant effect. CDGP was almost as common in male and female relatives of the CDGP subjects seen at specialist care, challenging the view of a marked overall male preponderance of CDGP.