A sporadic case of male-limited precocious puberty has the same constitutively activating point mutation in luteinizing hormone/choriogonadotropin receptor gene as familial cases
| Autor: | Leonard D. Kohn, Koichi Yano, Gordon B. Cutler, A Okuno, A Hidaka, M H Polymeropoulos, Motoyasu Saji |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty medicine.drug_class Inositol Phosphates Endocrinology Diabetes and Metabolism Molecular Sequence Data Clinical Biochemistry Glycine Puberty Precocious Biology Transfection medicine.disease_cause Chorionic Gonadotropin Polymerase Chain Reaction Biochemistry Deoxyribonuclease HpaII Protein Structure Secondary Endocrinology Japan Internal medicine Cyclic AMP medicine Humans Point Mutation Precocious puberty Deoxyribonucleases Type II Site-Specific Aspartic Acid Mutation Base Sequence Leydig cell Transition (genetics) Point mutation Biochemistry (medical) luteinizing hormone/choriogonadotropin receptor DNA Luteinizing Hormone Receptors LH medicine.disease Molecular biology medicine.anatomical_structure Child Preschool Mutagenesis Site-Directed Gonadotropin Luteinizing hormone |
| Zdroj: | The Journal of Clinical Endocrinology & Metabolism. 79:1818-1823 |
| ISSN: | 1945-7197 0021-972X |
| Popis: | Familial male-limited precocious puberty (FMPP) is an autosomal dominant disorder characterized by marked elevation of serum testosterone despite low levels of gonadotropin. Recently, a single point mutation in the LH/hCG receptor (LH/CGR) gene was found in FMPP families that constitutively activates the LH/CGR, causing Leydig cell activation and precocious puberty. Among the Japanese population, only four sporadic cases of male-limited precocious puberty have been reported. In the current study, we examined one of the four reported Japanese patients with sporadic male-limited precocious puberty and found the same mutation as that in the FMPP families. Genomic DNA was isolated, and the polymerase chain reaction (PCR) was performed to amplify a fragment of LH/CGR DNA encoding amino acid residues that include transmembrane helixes 5 and 6. Sequencing of the PCR products revealed a heterozygous adenosine-guanine transition at nucleotide 1733 in codon 578. The mutation encodes an aspartic acid578-glycine substitution in transmembrane helix 6. The mutant LH/CGR, created by site-directed mutagenesis in vitro, exhibited constitutively higher cAMP levels in transfected COS-7 cells than the wild-type LH/CGR, as described previously; however, basal inositol phosphate levels were not increased by transfection with complementary DNA for the mutant receptor. The concentration and affinity of [125I]hCG-binding sites were similar in cells transfected with the mutant and wild-type LH/CGR complementary DNAs, indicating that the mutant did not alter the production of receptor or its ability to bind human LH/CG. The sporadic occurrence of this case was confirmed by further studies. The mutation creates a recognition site for the restriction endonuclease MspI. Restriction digestion was positive for the mutant not digested by MspI, indicating that the patient's mutant allele was not inherited from his parents. DNA analysis of the patient and the parents, using microsatellite repeat markers, was compatible with biological paternity and maternity. We conclude that the aspartic acid578--glycine mutation in the LH/CGR has arisen in the Japanese population and is the cause of a sporadic case of male-limited precocious puberty. |
| Databáze: | OpenAIRE |
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