[Association analysis of autosomal dominant polycystic kidney disease in familial type in East-Azerbaijan]

Familial form of polycystic kidney disease which is inherited as an autosomal dominant pattern is one of the most common form of kidney disease. The main manifestation of this disease is the presence of growing cysts in kidney which results in malfunction of kidney. The frequency of disease is one in 1000 living birth. Mutation in one of the three different genes could result in developing polycystic kidney disease. Genetically analysis has been able to identify two of the genes, PKD1 and PKD2, located on chromosome 16 and chromosome 4 respectively. The location of the third gene remains unrevealed and the frequency of families affected due to the mutation on this gene is very low. By applying microsatellites tightly linked to the identified polycystic kidney disease genes, affected families referred from East Azerbaijan were genetically analyzed. Families with at least three affected members by polycystic kidney disease were studied. Polymorphic microsatellites from the regions of PKD1 and PKD2 were selected by studying the members of these families. All members of the families were investigated by the polymorphic markers to study linkage analysis. Out of 13 families with 99 members referred by specialists, 7 families with 75 members were selected on the base of availability. Disease in three of these families showed linkage with PKD2 gene and in one family linkage was found between the disease and PKD1 gene. In another family linkage was observed with neither PKD1 nor PKD2 genes. None of the markers were informative in two of the families; therefore these families were excluded from the studies. Most of the families with polycystic kidney disease from North West of Iran, showed linkage with PKD2 gene. One of the families did not show linkage with any of the known genes. In this family, disease could be due to mutation in the third gene which remains to be identified

[Genetic assessment of chromosome 21 microsatellites and their application in the diagnosis of down syndrome patients within an Eastern Azarbayjan population]

Down syndrome is one of the most common chromosome aneuploidies causing mental retardation which occurs in approximately 1/230 pregnancies. It is usually caused by the presence of an extra chromosome 21. The aim of this study was to evaluate the simple PCR based DNA diagnostic method and also to determine the parental origin of the extra chromosome 21 in trisomal Down syndrome. To determine the polymorphism rates of chromosome 21 microsatellite markers, 50 people from Eastern Azarbayjan were randomly selected and studied for the microsatellites. The results were statistically analyzed. Thirty affected Down syndrome patients, diagnosed by specialists were referred to the lab for further molecular analysis. After genetic counseling and getting consent, blood samples were obtained. Seven pairs of chromosome 21 microsatellite markers were amplified using PCR in all the samples. Five highly polymorphic microsatellite markers were selected from a total seven markers, studied in 50 normal people. Out of 30 Down syndrome's patients, trisomal 21 was diagnosed in 21 families [70%]. In which non-disjunction errors were determined to be of maternal origin in 86% and of paternal origin in 9% of the cases. The mean maternal and parental age was 33/3 and 36/2, respectively. The three microsatellite markers, D21S1910, D21S1411 and D21S11 could diagnose a high percentage of trisomal 21 in Down syndrome' patients. The parental origin of an extra copy of chromosome 21 could be exactly determined

Diagnosis and screening of spinal-muscular atrophy type III disease through PCR-RFLP in East Azarbaijan during 2004-2005

Hereditary pattern of spinal-muscular atrophy [SMA] disease is in form of recessive autosome with a frequency of 1 in 10000 live births. In most of the patients SMN1 gene bears deletions in exons 7 or 8. The aim of this study is to investigate deletion of above mentioned gene through molecular techniques in east Azarbaigan during 2004-2005. The patients likely to have SMA type III were referred to molecular study following the clinical and laboratory diagnosis. After extraction of DNA from patients' blood the extent of deletion in exons 7 and 8 of SMN1 gene, was investigated through PCR-Restriction Fragment Length Polymorphism [RFLP]. Out of 45 patients likely to have SMA type III, 9 people [20%] had exon deletion in SMN1 gene among whom one patient bore deletion only in exon 7 while the rest bore deletion in both exons [7, 8] of SMN1 gene. Deletion in SMN1 gene was observed in a low percent of the patients likely to have SMA type III. More research including the other sequences of SMN1 gene is recommended