RESUMO
OBJECTIVE: Nocturnal enuresis is defined as involuntary emptying of the bladder in the absence of an organic cause in a child aged 5 years or older. Primary nocturnal enuresis (PNE) is the term used if the child has never been dry. Of several factors implicated in the etiology of PNE, genetic factors appear to be the strongest. In about 75% of affected children, there is a strong family history. The purpose of this study was to examine the genetic basis of nocturnal enuresis among children in the United Arab Emirates (UAE). METHODS: Chromosomes 12 and 13 were genotyped in all family members of 10 affected children in four large families. Linkage to earlier reported microsatellite markers on these two chromosomes was examined. RESULTS: In the four families examined, we did not find evidence for linkage to the two loci reported previously. CONCLUSIONS: Among UAE children examined, no linkage was found between PNE and the loci reported previously on chromosomes 12 and 13, indicating further genetic heterogeneity in PNE.
Assuntos
Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 13/genética , Enurese Noturna/genética , Área Programática de Saúde , Pré-Escolar , Feminino , Ligação Genética/genética , Genótipo , Humanos , Masculino , Repetições de Microssatélites/imunologia , Enurese Noturna/etnologia , Linhagem , Emirados Árabes Unidos/epidemiologiaRESUMO
There are two highly homologous survival motor neuron (SMN) genes in humans but molecular defects in the SMN1 gene cause spinal muscular atrophy (SMA). More than 90% of SMA patients are shown to have a homozygous deletion of exon 7 in the SMN1 gene. Therefore, a simple test for exon 7 deletion would be very useful in the molecular diagnosis of SMA. However, limited methods are available, and most of these methods utilize expensive instruments and consumables. Here, we describe a simple allele-specific PCR test, which can be performed using standard equipment in DNA laboratories. The principle of the test is based on a single nucleotide difference (C versus T) between the exon 7 of SMN1 and SMN2 genes. Using allele-specific primers, two PCR amplifications are performed for each sample to amplify a 404-bp diagnostic fragment, and consequent electrophoresis of PCR products on agarose gel provides definitive information concerning the exon 7 deletion To rule out false negatives, a 500-bp fragment from the N-acetyltransferase gene was coamplified as an internal control in each test. We have, so far, analyzed 41 SMA samples with our method, and tested the validity of results using an independent restriction fragment length polymorphism (RFLP) method. Genotyping results obtained by both methods were in complete agreement for all of the samples analyzed. Our method can also be used to detect heterozygous deletion of exon 7 in SMN genes, if the relative intensities of the diagnostic and internal control bands are determined.
Assuntos
Éxons , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/genética , Proteínas do Tecido Nervoso/genética , Reação em Cadeia da Polimerase/métodos , Alelos , Arilamina N-Acetiltransferase/genética , Estudos de Casos e Controles , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Heterozigoto , Humanos , Polimorfismo de Fragmento de Restrição , Proteínas de Ligação a RNA , Reprodutibilidade dos Testes , Proteínas do Complexo SMN , Proteína 1 de Sobrevivência do Neurônio Motor , Proteína 2 de Sobrevivência do Neurônio MotorRESUMO
The angiotensin-converting enzyme (ACE) gene in humans contains an insertion-deletion polymorphism in its intron 16. Because of its involvement with the renin-angiotensin system, the insertion-deletion polymorphism of the ACE gene has been widely investigated in different populations and in case-control studies. However, similar studies for Arab populations are limited in number. Therefore we have investigated the frequencies of the *I and *D alleles of the ACE gene among Sudanese, Somalis, and Arab nationals of the United Arab Emirates and Oman using previously described methods. Our data indicate a preponderance of the *D allele among the Arab and African populations studied (Sudanese, 0.64; Somalis, 0.73; Emiratis, 0.61; and Omanis, 0.71).
Assuntos
Genética Populacional/métodos , Peptidil Dipeptidase A/genética , África Oriental , Alelos , Humanos , Oriente Médio , Reação em Cadeia da Polimerase , Polimorfismo GenéticoRESUMO
OBJECTIVE: To describe the angiotensin converting enzyme (ACE) genotype frequencies among Omani Arabs. METHOD: A polymerase chain reaction (PCR) test, based on separation of different size DNA fragments, was developed to test the presence or absence (polymorphism) of a small DNA deletion in the ACE gene. The subjects were 124 Omani Arab students of Sultan Qaboos University, Muscat. RESULTS: The frequency of the I allele was 0.29, while that of the D allele was 0.71. The gene frequency distribution did not deviate from Hardy-Weinberg equilibrium. CONCLUSIONS: The frequency of D allele among Omanis is similar to that among other Arabs and Africans, but differs significantly from that among the Japanese and Chinese.