Publications by authors named "Ridha M'Rad"

Article Synopsis
  • - Alport syndrome is a genetic disorder impacting the kidneys, ears, and eyes, caused by mutations in specific COL4A genes, with varying inheritance patterns including X-linked and autosomal recessive.
  • - A study involving 45 patients from Tunisian families revealed 9 likely pathogenic variants, including 6 new ones, mostly in COL4A3 and COL4A5, and confirmed that many siblings tested positive for the condition.
  • - The findings indicate that autosomal recessive inheritance may be more prevalent in Tunisia than previously thought, marking the first comprehensive screening of Alport syndrome mutations in the region.
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Background: Genetic cardiac diseases are the main trigger of sudden cardiac death (SCD) in young adults. Hypertrophic cardiomyopathy (HCM) is the most prevalent cardiomyopathy and accounts for 0.5 to 1% of SCD cases per year.

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Article Synopsis
  • Nephropathic cystinosis is an autosomal recessive disorder linked to mutations in the CTNS gene affecting lysosomal cystine transport, and this study focuses on the genetic traits specific to Tunisian children with the condition.
  • Researchers analyzed clinical data from 12 Tunisian patients and discovered a new mutation (c.971-1G > C) prevalent in half of the patients, indicating it might be a founder mutation; other mutations were also observed.
  • The findings suggest that mutation patterns in the Tunisian population differ from other regions, highlighting the need for tailored molecular diagnostics and early treatment initiatives in Tunisia.
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Background: Cockayne syndrome (CS) is a rare autosomal recessive disorder caused by mutations in ERCC6/CSB or ERCC8/CSA that participate in the transcription-coupled nucleotide excision repair (TC-NER) of UV-induced DNA damage. CS patients display a large heterogeneity of clinical symptoms and severities, the reason of which is not fully understood, and that cannot be anticipated in the diagnostic phase. In addition, little data is available for affected siblings, and this disease is largely undiagnosed in North Africa.

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Background: Li-Fraumeni syndrome (LFS) is a rare autosomal hereditary predisposition to multiples cancers, mainly affecting young individuals. It is characterized by a broad tumor spectrum. To our best knowledge, only one Tunisian study with a confirmed LFS was published.

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Background And Purpose: Warburg Micro syndrome (WARBM) is a rare autosomal recessive genetic disease characterized by ocular, neurologic, and endocrine anomalies. WARBM is a phenotypically and genetically heterogeneous syndrome caused by mutations in , , , and . Here we present the clinical and genetic characterization of a consanguineous Tunisian family with a WARBM phenotype presenting two pathogenic variations, one of which is on .

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Androgens are critical for male sex differentiation. Their actions are mediated by the androgen receptor (AR). Mutations disrupting AR function result in the androgen insensitivity syndrome (AIS).

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Background: Deleterious mutations on genes are known to confer high risk of developing breast and ovarian cancers. The identification of these mutations not only helped in selecting high risk individuals that need appropriate prevention approaches but also led to the development of the PARP-inhibitors targeted therapy. This study aims to assess the prevalence of the most frequent mutation in Tunisia, c.

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The Androgen insensitivity syndrome (AIS) in its complete form (CAIS) is a disorder in abnormal male development characterized by a complete female phenotype in a 46,XY individual. The most frequent cause of this disorder is a hemizygous mutation in androgen receptor (AR) gene located in X chromosome. The first aim of this study was to confirm the clinical diagnosis in a series of Tunisian patients with a typical phenotype of CAIS by molecular genetic analysis.

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Galloway-Mowat syndrome (GAMOS [MIM 251300]) is a rare autosomal recessive disorder that manifests as a combination of nephrotic syndrome, brain abnormalities and developmental delay. It is a clinically and genetically heterogeneous disease. The WDR73 variations are associated with GAMOS1.

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In humans, mutations of Desert Hedgehog gene (DHH) have been described in patients with 46,XY gonadal dysgenesis (GD), associated or not with polyneuropathy. In this study, we describe two patients diagnosed with GD, both harboring novel DHH compound heterozygous mutations p.[Tyr176*];[Asn337Lysfs*24] and p.

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Background: Autism spectrum disorder (ASD) comprises a group of neurodevelopmental psychiatric disorders characterized by deficits in social interactions, interpersonal communication, repetitive and stereotyped behaviors and may be associated with intellectual disabilities. The description of ASD as a synaptopathology highlights the importance of the synapse and the implication of ion channels in the etiology of these disorders.

Methods: A narrative and critical review of the relevant papers from 1982 to 2017 known by the authors was conducted.

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Poikiloderma with neutropenia (PN) is a genodermatosis characterized by poikiloderma, permanent neutropenia, recurrent infections, nail abnormalities, and palmoplantar hyperkeratosis. We report the case of a Tunisian patient with PN. Skin lesions started from the face and spread to the extremities and trunk.

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Juvenile myoclonic epilepsy (JME) is characterized by seizures, severe cognitive abnormalities, and behavior impairments. These features could evolve over time and get worse, especially when the encephalopathy is pharmacoresistant. Thus, genetic studies should provide a better understanding of infantile epilepsy syndromes.

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Complete gonadal dysgenesis (CGD) is characterized by an incomplete differentiation of the genital organs in a patient with a 46,XY karyotype. It is induced by mutations in the sex-determining region Y (SRY) gene which plays a key role in testis-determining pathways. The aim of this study was to investigate the possible pathogenic nature of a novel SRY mutation (p.

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Calcium plays a key role in cell signalling by its intervention in a wide range of physiological processes. Its entry into cells occurs mainly via voltage-gated calcium channels (VGCC), which are found not only in the plasma membrane of excitable cells but also in cells insensitive to electrical signals. VGCC are composed of different subunits, α1, β, α2δ and γ, among which the cytosolic β subunit (Cavβ) controls the trafficking of the channel to the plasma membrane, its regulation and its gating properties.

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Background: Marshall syndrome is a rare autosomal dominant skeletal dysplasia. It associates a particular facial dysmorphism with midface hypoplasia, ocular abnormalities and sensorineural hearing loss. It is caused by heterozygous mutations in COL11A1 gene coding the 1 chain of collagen XI.

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Article Synopsis
  • A study found that the Q318X mutation in the CYP21A2 gene is common in Tunisian patients with 21-hydroxylase deficiency, but also surprisingly present in 12.5% of healthy Tunisians.
  • Researchers used advanced PCR techniques to confirm that all identified carriers also had a duplicated CYP21A2 gene.
  • The findings suggest that the high frequency of this mutation complicates diagnoses, and further detailed analysis of the CYP21A2 region is recommended to differentiate between severe and normal variants of the Q318X mutation.
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A high incidence of de novo chromosomal aberrations in a population of persons with autism suggests a causal relationship between certain chromosomal aberrations and the occurrence of autism. A previous study on a Tunisian boy carrying a t(7;16) translocation identified the 7p22.1 as a positional candidate region for autism on chromosome 7.

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Autism is a pervasive developmental disorder characterised by impairment in social interaction and in communication, with unusual behaviour. Genetic factors are predominant in autism pathogenesis. Interactions between multiple genes cause "idiopathic" autism but epigenetic factors and exposure to environmental modifiers may contribute to variable expression of autism-related traits.

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Autism is a complex neurodevelopmental disorder characterized by impairment of social interaction, language, communication, and stereotyped, repetitive behavior. Genetic predisposition to autism has been demonstrated in families and twin studies. About 5-10% of autism cases are associated with chromosomal abnormalities or monogenic disorders.

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The high incidence of de novo chromosomal aberrations in a population of persons with autism suggests a causal relationship between certain chromosomal aberrations and the occurrence of isolated idiopathic autism. We report on the clinical and cytogenetic findings in a male patient with autism, no physical abnormalities and a de novo balanced (7;16)(p22.1;p16.

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Treacher Collins syndrome was first mentioned by Thompson in 1847, and described by Treacher Collins in 1900, then it was called mandibulo-facial dysostosis and well defined by Franceschetti in 1949. It is a very rare affection occurring lin 50.000 live births, which includes facial and auricular anomalies leading to functional, morphological and psychological difficulties due to related handicaps.

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Crigler-Najjar syndrome type I (CN-I) is a rare and severe metabolic disorder. A recurrent mutation - c.1070A>G in exon 3 - was identified in the Tunisian population, suggesting a founder effect.

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