Age and sexual maturation at Spermarche in boys with Laron syndrome.

OBJECTIVES: To determine the age at Spermarche in boys with Laron syndrome (LS), a model of genetic IGF-I deficiency. METHODS: Eight boys with LS and 70 healthy boys with familial short stature followed since early childhood reported the age at their first ejaculation (Spermarche) during examination of the pubertal stage. RESULTS: Spermarche in untreated boys with LS occurred at a mean chronological age of 19.1 ± 2.1 years compared to 14.3 ± 0.4 years in the healthy boys (p=0.002), but their bone ages were similar: 14.8 ± 1.3 vs. 13.5 ± 0.5 y (p=NS). The testicular volume at Spermarche in the untreated boys with LS was: 5.7 ± 1.3 mL compared to 10.0 ± 4.0 mL in the healthy boys (p<0.001). CONCLUSIONS: Determination of bone age is a practical indicator of sexual maturation including the appearance of Spermarche.