Spinal muscular atrophy (SMA) is the second most frequent autosomal recessive disease characterized by degeneration of the anterior horn cells of the spinal cord, leading to muscular atrophy. SMA is classified into three types according to disease severity and age-onset: severe (type I), intermediate (type II) and mild (type III). Deletions in the survival motor neuron (SMN) gene, located in the chromosome region 5q11.2-5q13.3, are major determinants of SMA phenotype. Extended deletions that include the neuronal apoptosis inhibitory protein (NAIP) gene may correlate with the severtity of SMA. SMN gene is present in two highly homologous copies, SMN1 and SMN2, but only deletions of the SMN1 gene (exons 7 and 8 or exon 7) are responsible for clinical manifestations of SMA. Here, we present the deletion profiling of SMN1 and NAIP genes in 89 children with SMA from Serbia: 52 patients with type I, 26 with type II, and 11 with type III. The homozygous deletion of the SMN1 gene was confirmed in 72 of 89 (81%) patients, being the most frequent in SMA type I (48/52): 68 patients (94.4%) with deletion of exons 7 and 8 and 4 patients (5.6%) with deletion of exon 7. The extended deletion including the NAIP gene was detected in 18 of 89 (20.2%) patients, mostly affected with type I. This study has revealed the lower incidence of deletions in the SMN1 and NAIP genes in families with SMA in Serbia and will provide important information for genetic counselling in these families.

Owing to disease severity and lack of a curative treatment, prenatal diagnosis of SMA is the best way to prevent recurrence. Carrier detection allows accurate risk assessment and appropriate genetic counseling for all family members.

The results of our pilot study justified the expanding of the routine neonatal screening program in Serbia with CF. Data could be used in future in order to obtain accurate incidence of CF and carrier prevalence in our country.

Fanconi anemia (FA) is a complex genetic disease with a variety of congenital and hematological symptoms, including the predisposition for cancer development. The main hallmark of FA cells, an increased chromosomal fragility, in the presence of the DNAinterstrand cross-linking chemicals, mitomycin C or diepoxybutane (DEB), makes the

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BackgroundPatients with Angelman syndrome (AS) are affected by severe intellectual disability with absence of speech, distinctive dysmorphic craniofacial features, ataxia and a characteristic behavioral phenotype. AS is caused by the lack of expression in neurons of the UBE3A gene, which is located in the 15q11.2-q13 imprinted region. Functional loss of UBE3A is due to 15q11.2-q13 deletion, mutations in the UBE3A gene, paternal uniparental disomy and genomic imprinting defects.Case presentationWe report here two patients with clinical features of AS referred to our hospital for clinical follow-up and genetic diagnosis. Methylation Specific-Multiplex Ligation-Dependent Probe Amplification (MS-MLPA) of the 15q11.2-q13 region was carried out in our laboratory as the first diagnostic tool detecting two novel UBE3A intragenic deletions. Subsequently, the MLPA P336-A2 kit was used to confirm and determine the size of the UBE3A deletion in the two patients. A review of the clinical features of previously reported patients with whole UBE3A gene or partial intragenic deletions is presented here together with these two new patients.ConclusionAlthough rare, UBE3A intragenic deletions may represent a small fraction of AS patients without a genetic diagnosis. Testing for UBE3A intragenic exonic deletions should be performed in those AS patients with a normal methylation pattern and no mutations in the UBE3A gene.

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The aim of the study was to estimate the type and the prevalence of chromosomal abnormalities and Y-chromosome microdeletions, analysed together for the first time in idiopathic infertile men in Serbia. During 10 years period among 823 couples with infertility problems, in 110 cases the cause of infertility was severe oligospermia or azoospermia in male partners. All of them underwent cytogenetic analysis, performed according to standard techniques. Testing for the presence of Y-chromosome microdeletions in AZF regions using multiplex PCR was done in all patients with normal karyotype (97) and in three cases with cytogenetically visible aberrations of Y chromosome, in order to specify the breakpoints. The overall prevalence of chromosomal abnormalities in the group of 110 infertile men was 11.82%. The most frequent aberration was Klinefelter syndrome (47, XXY), being found in 5.45%. Chromosomal aberrations 1010