CO-OCCURRENCE OF PRIMARY MICROCEPHALY CAUSED BY A NOVEL HOMOZYGOUS ASPM MUTATION ALONG WITH X-LINKED ICHTHYOSIS IN THE SAME PATIENT.

Autosomal recessive primary microcephaly is a heterogeneous genetic disorder caused by genes that affect neurogenesis. This form of microcephaly has not been associated with other congenital anomalies. ASPM mutations have been identified as the major cause implicated in autosomal recessive primary microcephaly. X-linked recessive ichthyosis, is an inborn error of steroid sulfatase metabolism characterized by dark and adhesive scaly skin. Here, we examined an Egyptian boy presenting with microcephaly and simplified gyral pattern. Additionally, he had ichthyosis that goes with the X-linked type. Mutation analyses of the ASPM gene for autosomal recessive primary microcephaly and STS gene of X-linked recessive ichthyosis were conducted revealing a co-occurrence of a novel homozygous splice site mutation of ASPM gene (c.2936+1G>A) and a partial deletion of STS spanning from exon 7-10. We propose that the phenotype of our patient results from the combined effects of mutations in both ASPM and STS that account for the neurological signs and skin manifestations, respectively. The association of isolated X-linked recessive ichthyosis and autosomal recessive primary microcephaly has never been reported in the literature. Careful clinical and genetic assessment of patients with atypical clinical phenotypes is crucial for detecting such rare double mutations and thus proper genetic counseling.

Bartsocas-Papas syndrome with variable expressivity in an Egyptian family.

Bartsocas-Papas syndrome (BPS) is an autosomal recessively inherited sublethal popliteal pterygium condition characterized by intrauterine or neonatal death, severe popliteal webbing, oligosyndactyly, ankyloblepharon, orofacial clefts, intraoral filiform bands and genital anomalies. Internal organ involvement has seldom been identified. We report on a 3 years old female patient of healthy first cousin parents with BPS. She presented with orofacial clefting, severe popliteal webs, club feet, oligosyndactyly of the toes, hypogenitalism and normal hands and internal organs. Ankyloblepharon and filiform bands between the alveolar ridges were evident at birth. Pedigree analysis revealed a more severely affected female sib, who died a few minutes after birth with additional manifestations including near complete lip fusion without oral cleft, complete syndactyly in both hands and an omphalocele. Linkage was excluded to the IRF6 gene; a candidate gene implicated in the Van der Woude and popliteal pterygium syndromes, with overlapping features with BPS. To our knowledge, this is the 5th surviving patient with this syndrome in the literature. In this report, we also discuss the proposed pathogenetic mechanisms for BPS and compare our patients with similarly described cases as well as overlapping spectrum of other popliteal pterygium syndromes. Our findings provide further evidence of intrafamilial clinical heterogeneity in families with BPS.

Screening for six Mediterranean mutations in 90 Egyptian patients with phenylketonuria.

OBJECTIVES: The aim of this study is to assess the prevalence of six common mutations in the Mediterranean basin and Turkey among a large group of Egyptian PKU cases BACKGROUND: Phenylketonuria (PKU) is one of the most common inborn errors of amino acid metabolism that is caused by deficiency of hepatic phenylalanine hydroxylase (PAH). This deficiency is attributed to more than 528 mutations in the PAH gene. METHODS: Ninety unrelated patients with PKU (180 alleles) were screened for six mutations (IVS10-11G>A, R261Q, R252W, Y277D, E221G and G272S) using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The IVS10-11G>A mutation was found in thirty alleles (17%), the R261Q in twelve (7%) and R252W in three (1.6%), while Y277D, E221G and G272S were not found in this patient group. CONCLUSION: Screening for six Mediterranean mutations identified a heterogeneous pattern among Egyptian PKU patients with a high frequency of IVS10-11 G>A (17%) (Tab. 2, Ref. 31). Full Text (Free, PDF) www.bmj.sk.

Molecular analysis of SMN1 and NAIP genes in Egyptian patients with spinal muscular atrophy.

OBJECTIVES: The aim of this study is to provide preliminary molecular data on spinal muscular atrophy in Egyptian patients thus facilitating a rapid and conventional molecular assay for accurate diagnosis of SMA. BACKGROUND: Childhood spinal muscular atrophy (SMA) is one of the most common autosomal recessive disorders. It is characterized by symmetrical muscle weakness and atrophy of limbs and trunk. At least four SMA related genes have been identified [survival motor neuron (SMN), neuronal apoptosis inhibitory protein (NAIP), the gene encoding the transcriptional factor p44 and H4F5 gene]. METHODS: Homozygous absence of exons 7 and 8 of the SMN1 gene was detected using PCR-SSCP analysis, while NAIP gene deletion was detected using multiplex PCR-agarose gel electrophoresis. RESULTS: Homozygous absence of SMN1 exons 7 and 8, or exon 7 only, was found in 80% of patients. Of those patients, 45% were also deleted for NAIP exon 5. CONCLUSION: The molecular basis of SMA in Egyptian patients has a similar pattern to that reported in most populations, but a larger study is recommended for more comprehensive characterization (Tab. 1, Fig. 2, Ref. 33).

The milder phenotype of the dystrophin gene double deletions.

OBJECTIVES: This study aimed to examine the genotypephenotype correlation in Duchenne muscular dystrophy (MD) patients with double deletion (Ddel) mutations in comparison with those having single deletions (Sdel). MATERIALS AND METHODS: The study included 250 Duchenne/Becker MD male patients from whom the 10 Ddel patients were compared with 20 Sdel subjects of same age and disease durations. The patients were subjected to neurological examination including functional disability grading scale (FDGS), molecular analysis of the dystrophin gene and immunohistochemical studies of some muscle biopsies. RESULTS: The mean FDGS value in the Ddel group was lower than that in Sdel patients. The Ddel patients had partial expression of dystrophin in their skeletal muscles, while Sdel cases showed complete absence of the protein. CONCLUSION: Patients with double deletion mutations within the dystrophin gene have a milder phenotype than patients harboring single deletions at either major or minor hot spots of the gene.

Schistosoma hematobium soluble egg antigens induce proliferation of urothelial and endothelial cells.

Bladder carcinoma accounts for 26% of reported human malignancies in Egypt, and has been strongly associated with urinary schistosomiasis. Nevertheless, the immediate role of schistosomal egg proteins in bladder carcinogenesis is unexplored. We investigated the effects of crude soluble egg antigens (SEA) of Schistosoma hematobium on urothelial cell proliferation. The proliferation of bovine endothelial Endo, human urothelial J82 and smooth muscle SMC cell lines was assessed by low-density growth assays. SEA induced proliferation of both J82 and Endo cells in a dose-dependent fashion, but not SMC. Preboiling or proteinase K treatment of SEA abolished its effect. In addition, SEA enhanced urothelial expression of B-cell translocation protein (BTG1) and human proliferating cell nuclear antigen (PCNA) mRNAs. Given the strong correlation between cell proliferation and carcinogenesis, the findings suggest that crude SEA may play some role in schistosomal bladder carcinogenesis.

Screening of dystrophin gene deletions in Egyptian patients with DMD/BMD muscular dystrophies.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations within the dystrophin gene. Our study has identified 100 Egyptian families collected from the Human Genetics Clinic, National Research Center, Cairo. All cases were subjected to complete clinical evaluation pedigree analysis, electromyography studies, estimation of serum creatine phosphokinase enzyme (CPK) levels and DNA analysis. Multiplex PCR using 18 pairs of specific primers were used for screening of deletion mutations within the dystrophin gene. A frequency of 55% among the families. Sixty per cent of detected deletions involved multiple exons spanning the major or the minor hot spot of the dystrophin gene. The remainder 40% which mainly involved exon 45. Comparing these findings with frequencies of other countries it was found that our figures fall within the reported range of 40%- distribution of deletions in our study and other different studies was variable and specific ethnic differences do not apparently account for specific deletions. In addition this study concluded that employment of the 18 exon analysis is a cost effective and a highly accurate (97% to launch a nationwide program.

Haplotypes and mutations of the PAH locus in Egyptian families with PKU.

A high degree of molecular heterogeneneity at the phenylalanine hydroxylase (PAH) locus was established by examining RFLP haplotypes and PAH mutations in the families of 13 Egyptians with phenylketenouria (PKU). Thirteen different haplotypes were unequivocally determined in these kindreds. Haplotypes 1.8, 3.9, 4.3, 7.8, 22.11, 27.6, and 52.8 were found segregating with normal chromosomes, whilst haplotypes 1.8, 5.9, 23.8, 32.8, the newly assigned 73.9, and two as yet incomplete but novel haplotypes were found segregating with the mutant chromosomes. There was no particular preference for a single haplotype among normal or mutant chromosomes. Nine different mutations were also identified among the 26 alleles. IVS 10nt11g (8/26), IVS 2nt5g-c (4/26), R261Q (3/26), R176X (2/26), Y206D (2/26), S231P (2/26), Y198fs [593-614del22bp]; (2/26), G46fs [136/137delG]; (1/26), and E178G (1/26). Six of these mutations (IVS 2nt5g-c, R176X, Y198fs, R261Q, S231P, and IVS 10nt11g) are common to other Mediterranean populations. Two mutations not previously reported in the Mediterranean basin were also observed (Y206D and G46fs). These intriguing preliminary findings confirm IVS 10nt11g as a major mutation among Mediterranean mutations and demonstrate the need for a more comprehensive study of Arab populations to confirm the uniqueness of the two novel mutations to the Egyptian population.