A novel missense mutation p. L76P in the GJB2 gene causing nonsyndromic recessive deafness in a Brazilian family

Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of nonsyndromic recessive hearing loss in many countries. We report here on a novel point mutation in GJB2, p.L76P (c.227C>T), in compound heterozygosity with a c.35delG mutation, in two Brazilian sibs, one presenting mild and the other profound nonsyndromic neurosensorial hearing impairment. Their father, who carried a wild-type allele and a p.L76P mutation, had normal hearing. The mutation leads to the substitution of leucine (L) by proline (P) at residue 76, an evolutionarily conserved position in Cx26 as well as in other connexins. This mutation is predicted to affect the first extracellular domain (EC1) or the second transmembrane domain (TM2). EC1 is important for connexon-connexon interaction and for the control of channel voltage gating. The segregation of the c.227C>T (p.L76P) mutation together with c.35delG in this family indicates a recessive mode of inheritance. The association between the p.L76P mutation and hearing impairment is further supported by its absence in a normal hearing control group of 100 individuals, 50 European-Brazilians and 50 African-Brazilians.

Association of polymorphisms at the ADIPOR1 regulatory region with type 2 diabetes and body mass index in a Brazilian population with European or African ancestry

Association studies between ADIPOR1 genetic variants and predisposition to type 2 diabetes (DM2) have provided contradictory results. We determined if two single nucleotide polymorphisms (SNP c.-8503G>A and SNP c.10225C>G) in regulatory regions of ADIPOR1 in 567 Brazilian individuals of European (EA; N = 443) or African (AfA; N = 124) ancestry from rural (quilombo remnants; N = 439) and urban (N = 567) areas. We detected a significant effect of ethnicity on the distribution of the allelic frequencies of both SNPs in these populations (EA: -8503A = 0.27; AfA: -8503A = 0.16; P = 0.001 and EA: 10225G = 0.35; AfA: 10225G = 0.51; P < 0.001). Neither of the polymorphisms were associated with DM2 in the case-control study in EA (SNP c.-8503G>A: DM2 group -8503A = 0.26; control group -8503A = 0.30; P = 0.14/SNP 10225C>G: DM2 group 10225G = 0.37; control group 10225G = 0.32; P = 0.40) and AfA populations (SNP c.-8503G>A: DM2 group -8503A = 0.16; control group -8503A = 0.15; P = 0.34/SNP 10225C>G: DM2 group 10225G = 0.51; control group 10225G = 0.52; P = 0.50). Similarly, none of the polymorphisms were associated with metabolic/anthropometric risk factors for DM2 in any of the three populations, except for HDL cholesterol, which was significantly higher in AfA heterozygotes (GC = 53.75 ± 17.26 mg/dL) than in homozygotes. We conclude that ADIPOR1 polymorphisms are unlikely to be major risk factors for DM2 or for metabolic/anthropometric measurements that represent risk factors for DM2 in populations of European and African ancestries.

Reverse transcription-polymerase chain reaction assay for rabies virus detection

Este estudo teve por objetivo implantar um protocolo de amplificação genômica, precedida de transcrição reversa (RT-PCR) para o gene da nucleoproteína do vírus da raiva, para a utilização dessa metodologia em laboratórios onde são realizadas investigações para a detecção do vírus rábico. Foram utilizadas 50 amostras de tecido encefálico de animais (44 bovinos, 5 eqüinos e 1 quiróptero) oriundos do Estado do Rio de Janeiro, positivos por imunofluorescência direta e/ou prova biológica para o vírus rábico. A extração do RNA foi feita a partir da suspensão a 10 por cento em PBS pH7,2 do tecido encefálico utilizando-se a metodologia de TRIzolTM (Life Technologies) e o protocolo de RT-PCR descrito por Heaton et al. (1997), incluindo algumas modificações. Dentre as 50 amostras analisadas, 50 foram positivas pela prova biológica e pela RT-PCR e destas, 49 foram positivas pela imunofluorescência direta. Estes resultados demonstram ser este protocolo de RT-PCR uma metodologia sensível, específica, rápida e extremamente valiosa, podendo ser utilizada como rotina em laboratórios que trabalham no diagnóstico de vírus rábico.

Cisto testicular em carpa comum

São descritas duas formações císticas no testículo direito de um exemplar de carpa comum ( Cyprinus carpio). O cisto maiormedia Sem de diâmetro e o menor 0,5cm, de paredes finas, sendo preenchidos por um líquido amarelo-claro transparente.Microscopicamente, o testículo mostrava um severo processo atrófico ·relacionado com extensa proliferação conjuntiva.