Childhood growth of females with Kallmann syndrome and FGFR1 mutations.

Abstract

In search of phenotypic cues that would allow early detection of Kallmann syndrome (KS), we evaluated the paediatric phenotypes in a series of females with KS. In this retrospective cohort study, we investigated childhood growth in six females with KS due to mutations in FGFR1 and evaluated their reproductive phenotypes later in life. While growth during early infancy and childhood was within normal limits, a decreasing trend in height SDS already from mid-childhood occurred in most patients. The lowest height SDS (mean, -1·2 SDS) occurred between 14 and 15 years of age, before the start of hormone replacement therapy. As adults, these women required assisted reproductive techniques for fertility. One of the probands passed on her G48S mutation to her son, who showed normal reproductive hormone levels during the minipuberty of infancy. Early diagnosis of female KS remains a challenge as early phenotypic signs, apart from anosmia, are scarce. Females with KS exhibit a slight reduction in growth rate during mid-childhood, but normal growth rate during the minipuberty of infancy, despite congenital lack of ovarian oestrogen. Women harbouring FGFR1 mutations will have 50% chance of passing on the gene defect to their offspring. We recommend genetic counselling to all females with KS to be carried out as a part of family planning.