ABSTRACT
Primary ciliary dyskinesia (PCD) is a genetically heterogeneous hereditary disease caused by the structural abnormalities and dysfunction of motile cilia. The DNAH5 is the most frequently mutated gene in PCD patients and hot spot exons were reported in this gene. Here, we aim to screen mutations in a set of five hot spot exons of DNAH5 gene in a cohort of 10 clinically diagnosed Tunisian PCD patients using an optimized polymerase chain reaction-single-strand conformational polymorphism screening technique. Only one patient harboured a novel heterozygous variant in exon 63 (c.10767A[G), which was inherited from his father. This variant activates a cryptic splicing site. No deleterious mutation has been identified while screening the exons of the remaining patients. Our results show that the reported hot spot exons of DNAH5 gene are not mutated in Tunisian PCD patients. This is probably due to the differences of ethnical background of the previously reported patients. Further investigations should be performed to identify the mutations underlying PCD in this group of patients.
ABSTRACT
Background: Ataxia-telangiectasia [A-T] is a multisystem disorder characterized by progressive neurologic impairment, variable immunodeficiency, impaired organ maturation, X-ray hypersensitivity, oculocutaneous telangiectasia, and a predisposition to malignancy
Aim: We performed this study in order to describe clinical, immunological and molecular features of patients with AT followed in the south of Tunisia
Methods:we performed a retrospective study [1996-2012] in the south of Tunisia about all cases of A-T in order to describe their clinical, immunological and molecular features
Results:11 cases of AT were found. The mean age at onset of symptoms was 20 months with extremes varying from 3 months to 4 years. The median time to diagnosis was 3.6 years [range: 0-12 years].The main clinical feature of cerebellar syndrome, ataxia, was present at diagnosis in 8 patients and occurred at mean ages of 2.8 years. Ocular telangiectasia occurred at a mean age of 3.9 years [extremes: 3 months and 7 years]. Recurrent sino-pulmonary infections that affected 7 children occurred at the mean age of 4.3 years. The most common humoral immune abnormality was serum IgA deficiency. Lymphopenia was found in 7 cases and lack of CD4 T in 6 cases. Cytogenetic analyses showed chromosomal instability in all children and a translocation [7-14] in two patients. A molecular diagnosis established in 6 patients from 4 families showed 5 different mutations of ATM gene. After an average decline of 5 years and 6 months, 7 patients died of severe pulmonary infection. Among them, 3 were ATM mutated
Conclusion: Morbidity and mortality among patients with A- T are associated with ATM genotype