Background: Spinal muscular atrophy includes a group of neuromuscular disorders characterized by degeneration of anterior horn cells in the spinal cord, and leads to progressive muscular weakness. NAIP is one of the genes that inhibits motor neuron apoptosis. Deletion of this gene is usually observed in type I SMI. The aim of this study was to investigate the frequency and pathogenicity of NAIP gene among SMA patients in east Azerbaijan and neighboring regions within the years 2004-2005. Materials and Methods: This descriptive study was carried out on 50 patients suffering from SMA by extracting DNA and molecular genetic survey of the samples. Exons 5 and 13 of NAIP gene and microsatellite D5S1416 were amplified using polymerase chain reaction (PCR) and the product on agar gel and polyacrylamid gel was put on electrophoresis through ethidium bromide stain and silver nitrate stain respectively and the frequency of different types of SMA with NAIP gene deletion was calculated. To determine the relation between gender and disease intensity test was used. Results: Out of 50 SMA patients 28% showed deletion in NAIP gene all belonging to type I of the disease with the highest disease intensity. Nine patients (64%) with deleted NAIP gene were the outcome of consanguineous marriage. Disease intensity in type I patients lacking NAIP gene was higher than type I patients with healthy genes. Conclusion: In 28 percent of patients NAIP deletion was observed. Consanguineous marriage is a promoting factor in gene mutation purification and birth of diseased neonates in studied samples. It is recommended that the families with SMA background refer to molecular genetic centers for prenatal diagnosis and close relatives avoid consanguineous marriage.

Background & Objective: 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.
Materials & methods: 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.
Results: 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.
Conclusion: The three microsatellite markers, D21S1910, D21S1411 & 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.