Análise da frequência de polimorfismos no gene LHB e parâmetros clínicos em portadoras de síndrome de ovários policísticos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Introduction: The polycystic ovary syndrome (PCOS) is an endocrinopaty characterized by chronic, discontinuous anovulation and excess of androgens, which leads to oligo or amenorrhea, hirsutism, acne and androgenic alopecia. There are many theories to explain the phisiopatogenics of the PCOS, and it is also related to the metabolic syndrome. Recent findings have pointed to the influence of molecular variants of the LH at the origins of PCOS. Objective: To access the rate of polymorphisms in the LHB (beta-subunit luteinizing hormone) gen in women with PCOS and to analyze the association between such polymorphisms and clinical features of PCOS and metabolic syndrome (MS). Methods: Transversal study. Fifty women previously diagnosed with PCOS by Rotterdam criteria were evaluated. Physical and laboratory exams defined the different PCOS and MS clinical presentations. Genetic sequencing of the LHB gen was performed in order to access the occurrence of polymorphisms. The possible relations between single polymorphisms, genetic profile and haplotypes to the PCOS and MS clinical presentation were then analyzed. Results: The Ferriman Gallwey index revealed statistically different means between polymorphisms rs1800447 / rs34349826 (p = 0,001), rs1056914 (p = 0,01), rs2387588 / rs427687 (p = 0,04) and rs1056917 (p = 0,02) and the haplotypes TTCATACT e CCGAC-CC (odds ratio: 4,2 e 19,1 respectively). As to the clinical criteria for PCOS, there was a higher grade of hirsutism when occurring the allelic variant C with the rs1800447 / rs34349826 polymorphisms (p = 0,04) and also with th haplotype TTCATACT (OR: 0,4). Laboratorial hyperandrogenism, evaluatedby testosterone serum concentration, showed that the haplotypes CCGAC-CC, TTGATACT and TTGCTACC had a positive odds ratio (45,5, 2,1 and 39,1, respectively), and the opposite occurred with TTCCC-CC, TTCATACC and TTCATAAT (odds ratio: -6,6; -22,5; -22,6, in that order). One new mutation, not previously reported, at base 1430, éxon 3, by exchanging a cytosine for an adenine, was found, but it presented with no influence at the PCOS and MS variables. Conclusion: The frequency found for polymorphisms at the LHB gene in 50 Brazilian women with POS was similar to that described at the literature. The rs1800447 / rs34349826 polymorphism presented was associated with higher hirsutism grade by the Ferriman-Gallwey index. Similar results were found for the genetic profiles and also the haplotype TTCATACT. As for laboratorial hyperandrogenism, higher serum testosterone concentration was present with the haplotypes CCGAC-CC, TTGATACT and TTGCTACC. However, a protective effect was found for the haplotypes TTCCC-CC, TTCATACC and TTCATAAT. The findings regarding the MS criteria revealed not to be significant.

ASSUNTO(S)

síndrome dos ovários policísticos subunidade beta hormônio luteinizante hirsutismo endocrinologia polycystic ovary syndrome beta-subunit síndrome metabólica hirsutism luteinizing hormone metabolic syndrome

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