• PMID: 17554105
• Gene Name: FGFR3
• Condition: Klinefelter patient
• Association: The observed testicular size and function in our patient contrast the typical findings in classical Klinefeltersyndrome. The study speculates that the alteration of FGFR3 protein function in our Klinefelter patient alleviated the destruction of the semini
• Mutation: non-mosaic 47,XXY karyotype, 1138G>A mutation
• Population size: 1
• Population details: 1 Klinefelter syndrome
• Sex: Male
• Infertility type: Male infertility
• Other associated phenotypes: Klinefelter patient

Preserved fertility in a non-mosaic Klinefelter patient with a mutation in the fibroblast growth factor receptor 3 gene: case report

Juul A, Aksglaede L, Lund AM, Duno M, Skakkebaek NE, Rajpert-De Meyts E.

Patients with Klinefelter syndrome (47,XXY) are characterized by eunuchoid body proportions, gynaecomastia, small firm testes and azoospermia. We describe a Klinefelter patient (non-mosaic 47,XXY karyotype) who was heterozygous for the classical 1138G>A mutation in the fibroblast growth factor receptor 3 (FGFR3) gene, which is a gain-of-function mutation resulting in achondroplasia. The patient had phenotypic characteristics of achondroplasia (e.g. short limbed dwarfism and frontal bossing). Testicular volume was 8 ml at 27 years of age and repeated semen samples showed sperm concentrations of 0.175 million/ml. Serum FSH levels were elevated (21.7 IU/l) compared to normal age-matched healthy male controls and patients with non-mosaic Klinefelter syndrome, and inhibin B levels were low-normal, in contrast to the usually undetectable inhibin B levels in adult Klinefelter patients. The patient fathered a child from a spontaneous pregnancy. The observed testicular size and function in our patient contrast the typical findings in classical Klinefelter syndrome. We speculate that the alteration of FGFR3 protein function in our Klinefelter patient alleviated the destruction of the seminiferous tubules and may suggest that the fibroblast growth factor family has a pleiotrophic function in human spermatogonia, which physiologically express FGFR3. FAU - Juul, A AU - Juul A AD - Department of Growth and Reproduction GR, Rigshospitalet Section 5064, University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark. ajuul@rh.dk FAU - Aksglaede, L AU - Aksglaede L FAU - Lund, A M AU - Lund AM FAU - Duno, M AU - Duno M FAU - Skakkebaek, N E AU - Skakkebaek NE