Polimorfismo do gene do receptor de insulina (INSR) em pacientes com síndrome dos ovários policísticos / Polymorphims of the insulin receptor gene (INSR) in patients with polycystic ovary syndrome

OBJETIVO: Avaliar a freqüência do polimorfismo do gene (INSR), localizado no éxon 17 do cromossomo 19, quanto ao seu envolvimento na predisposição genética da SOP e a associação com a sensibilidade à insulina e hiperandrogenismo. MATERIAL E MÉTODOS: Foram estudadas 57 pacientes com SOP e 50 mulheres normais com ciclos menstruais regulares (controle) quanto à frequência de polimorfismos de nucleotídeo único (Single Nucleotide Polymorphisms–SNPs) do gene INSR, através da análise de comprimento do fragmento de restrição (Restriction Lengh Fragment Polymorphisms-RFLPs). Para avaliar a sensibilidade à insulina, utilizou-se os seguintes métodos matemáticos: relação glicemia/insulina de jejum (G/I), Homeostasis Model Assessment (HOMA) e Quantitative Sensitivity Check Index (QUICKI). Foram considerados normais, G/I maior ou igual a 4,5, HOMA menor que 3,8, e QUICKI maior ou igual a 0,34. RESULTADOS: O polimorfismo (C/T, T/T) na SOP não apresentou diferenças significativas com o grupo controle. Quanto a insulinemia, não observamos diferenças entre as pacientes com genótipos (C/T, T/T) e (C/C). CONCLUSÕES: As frequências do polimorfismo do gene INSR, são semelhantes tanto em pacientes com SOP, como em mulheres normais. Esses genótipos (C/T e T/T) não influenciam a sensibilidade à insulina e o hiperandrogeninsmo na SOP

The 3´-untranslated ApaI-Insulin-like Growth Factor II Gene (IGF2) Polymorphism in Women with Uterine Leiomyomas

OBJECTIVE: To explore a possible association betweenthe rare allele A of the single nucleotide polymorphismin the 3´-untranslated region of the insulin-like growthfactor II gene (IGF2), previously described as beingassociated with growth dysregulation, higher body massindex (BMI), and elevated risk of uterine leiomyomas.MATERIALS AND METHODS: A series of 144 women(72 clinically and histologically confirmed uterineleiomyomas and 72 without leiomyomas) was analyzedby a PCR-RFLP (Polimerase Chain Reaction – RestrictionFragment Length Polymorphism) based approach todetect a single nucleotide polymorphism in the 3´-untranslated region of the gene IGF2. Genotypic andallelic frequencies distributions in both groups werecompared with weight, height, and BMI. RESULTS: Nostatistically significant differences in the genotype andallelic frequencies between patients and controls wereobserved. Similarly, the distribution of genotypes andweight, height, and BMI did not differ significantlybetween the two groups although the weight and BMIwere lower in leiomyomas patients homozygous forallele A. CONCLUSIONS: The ApaI polymorphism ofthe IGF2 gene does not produce different risk forleiomyoma development. Our data suggest that thedeviations related in the genotypic frequencies for thispolymorphism among women with uterine leiomyomasis not correlated with BMI and that previous associationswere probably a result of chance statistical samplingpresent in a small studied group.

Clonal chromosome abnormalites found in three non-neoplastic proliferative brain lesions

Chromosome analysis was made of brain lesions from three patients which, according to classical histopathological criteria, did not contain tumor cells. In addition to normal cells, we identified abnormal karyotypes with clonal numerical and structural chromosome alterations in at least two independently originated primary cultures from each lesion. Our data suggest that chromosomal aberrations can exist in vivo in non-neoplastic lesions. Other abnormalities may be due to genetic instability manifested only in vitro (culture artifacts) or may already have been present in brain tissue, reflecting previous chromosome damage (as a result of exposure to chemical treatment or enviromental clastogens).