The Boy:Girl Ratio of Children Diagnosed with Growth Hormone Deficiency-Induced Short Stature Is Associated with the Boy:Girl Ratio of Children Visiting Short Stature Clinics.

BACKGROUND: About twice as many boys as girls undergo growth hormone (GH) therapy in GH deficiency (GHD). However, this sex difference may not correctly reflect a real incidence. OBJECTIVES: We analyzed the evidence of a selection bias whereby more boys seek treatment at short stature clinics. SUBJECTS AND METHODS: The present study included 3,902 children who visited 17 short stature clinics with a height SD score of -2 SD or less. The percentage of children who underwent the GH stimulation test was compared between boys and girls, as was the percentage of children ultimately diagnosed with GHD. RESULTS: The children comprised 2,390 boys (61.3%) and 1,512 girls (38.7%), with a boy:girl ratio of 1.58:1. The percentage of children who underwent the GH stimulation test did not differ between boys (45.7%) and girls (49.8%). Among the children who underwent the GH stimulation test, the percentage diagnosed with GHD did not differ significantly between boys (22.0%) and girls (20.1%). The boy:girl ratio of children diagnosed with GHD was 1.59:1. CONCLUSIONS: The boy:girl ratio of children with short stature (1.58:1) did not differ significantly from that of children diagnosed with GHD (1.59:1). These results indicate that the predominance of boys in GHD does not reflect a real incidence, but rather a selection bias whereby a higher proportion of boys with short stature seek treatment at clinics. This difference arises because parents are more concerned about boys' height, and because boys reach adult height at an older age.

Difference between Japanese and Caucasian populations in the allelic frequency of growth hormone receptor polymorphisms.

BACKGROUND: Polymorphisms in the growth hormone receptor (GHR) gene were reported in Caucasian populations. However, the frequency of those in other ethnic backgrounds remains unclear. AIM: We investigated the presence of polymorphisms in the GHR gene in a Japanese population and compared the frequencies with those reported in Caucasian populations. POPULATION: We selected 30 children with idiopathic short stature and 30 adult Japanese of normal height. METHODS: The sequences of exons 6 and 10 in the GHR gene were determined by direct sequencing by polymerase chain reaction (PCR). The genomic deletion of exon 3 (GHR-d3) was investigated by multiplex PCR. RESULTS: The frequency of the GGG genotype at codon 168 was significantly higher than that reported in Caucasian populations. The frequency of GHR-d3 in Japanese was significantly lower than that in Caucasian populations. CONCLUSIONS: The frequencies of the G168G polymorphism and GHR-d3 in Japanese are different from those in Caucasians.

Congenital combined pituitary hormone deficiency attributable to a novel PROP1 mutation (467insT).

BACKGROUND: Combined pituitary hormone deficiency (CPHD) is an anterior pituitary disorder, commonly resulting in growth retardation. PROP1 gene mutations appear to be frequently responsible for CPHD, particularly in Middle and Eastern Europe and the Americas, but few cases have been reported in Japan. PATIENTS AND DESIGN: Two sisters (aged 8.4 and 4.3 years at presentation) exhibited proportional short stature from about 2 years of age. Genetic analysis determined the nature and location of mutations. RESULTS: Pituitary size by magnetic resonance imaging (MRI) indicated only slight hypoplasia, while hormone analysis revealed deficiencies in secretion of growth hormone (GH), thyroid stimulating hormone, prolactin and gonadotropins; adrenocortinotropin secretion appeared adequate. Genetic analysis revealed a novel familial inherited PROP1 mutation. A unique insertion mutation was found in codon 156 (467insT) located in the transcription-activating region of the PROP1 gene. The resulting PROP1 protein (191 amino acids) would lack the transcription activation domain and consequently be non-functional. CONCLUSION: Gene analysis suggested that the siblings had inherited a unique autosomal recessive PROP1 gene mutation resulting in severe GH deficiency and subsequent growth retardation.