Genetic heterogeneity of activating mutations of the luteinizing hormone receptor gene in familial male-limited precocious puberty

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Journal of Human Genetics

OSTI ID:134243

Laue, L; Chan, W Y; Wu, S M ^[1]

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1. Georgetown Univ. Medical Center, Washington, DC (United States); and others

Familial male-limited precocious puberty (FMPP) is an autosomal dominant disorder characterized by elevated serum levels of testosterone, low levels of gonadotropins, and Leydig cell hyperplasia. Recently, 3 mutations have been found in FMPP families which encode substitution of Gly for Asp 578, Ile for Met 571, and Ile for Thr 577 in transmembrane helix 6 (TM 6) of the luteinizing hormone receptor (LHR). We have studied 28 additional unrelated FMPP families. Genomic DNA was isolated from affected males and PCR was performed to amplify a fragment of the LHR gene encoding amino acid residues 441 to 594. MspI restriction enzyme digests were positive for the Asp 578 to Gly mutation in 22 families. Four new mutations were found in the remaining 6 families: an A to C transition encoding substitution of Leu for Ile 542 in transmembrane helix 5 (TM 5), an A to G transition encoding substitution of Gly for Asp 564 in the third cytoplasmic loop, a G to T transition encoding substitution of Try for Asp 578 in TM 6, and a T to C transition encoding substitution of Arg for Cys 581 in TM 6 of the LHR. 293 cells transfected with cDNAs for each of the 4 mutant LHRs, created by site-directed mutagenesis of the wild-type LHR cDNA, exhibited markedly increased levels of basal cAMP production in the absence of agonist, indicating constitutive activation of the mutant LHRs. We conclude that substitution of residues at multiple sites with TM 5, TM 6, and the intervening third cytoplasmic loop of the LHR cause constitutive receptor activation resulting in FMPP. These findings allow future diagnosis of affected patients and provide the basis to study the receptor domains involved in G-protein activation.

• OSTI ID: 134243
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
AMINO ACIDS
DIAGNOSIS
DOMINANT MUTATIONS
GENE MUTATIONS
GENES
HEREDITARY DISEASES
LH
MALES
POLYMERASE CHAIN REACTION
PROTEINS
RECEPTORS
UROGENITAL SYSTEM DISEASES