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After publication of the original article [1] it was brought to our attention that author Bouchra Ouled Amar Bencheikh was incorrectly included as Bouchra Oulad Amar Bencheikh.
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BACKGROUND: Epilepsy regroups a common and diverse set of chronic neurological disorders that are characterized by spontaneous, unprovoked, and recurrent epileptic seizures. Epilepsies have a highly heterogeneous background with a strong genetic contribution and various mode of inheritance. X-linked epilepsy usually manifests as part of a syndrome or epileptic encephalopathy. The variability of clinical manifestations of X-linked epilepsy may be attributed to several factors including the causal genetic mutation, making diagnosis, genetic counseling and treatment decisions difficult. We report the description of a Moroccan family referred to our genetic department with X-linked epileptic seizures as the only initial diagnosis. CASE PRESENTATION: Knowing the new contribution of Next-Generation Sequencing (NGS) for clinical investigation, and given the heterogeneity of this group of disorders we performed a Whole-Exome Sequencing (WES) analysis and co-segregation study in several members of this large family. We detected a novel pathogenic PLP1 missense mutation c.251C > A (p.Ala84Asp) allowing us to make a diagnosis of Pelizaeus-Merzbacher Disease for this family. CONCLUSION: This report extends the spectrum of PLP1 mutations and highlights the diagnostic utility of NGS to investigate this group of heterogeneous disorders.
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Secuenciación del Exoma , Mutación Missense , Proteína Proteolipídica de la Mielina/genética , Enfermedad de Pelizaeus-Merzbacher/diagnóstico , Enfermedad de Pelizaeus-Merzbacher/genética , Preescolar , Familia , Femenino , Marcadores Genéticos , Humanos , Masculino , Marruecos , LinajeRESUMEN
Anauxetic dysplasia (AAD, OMIM 607095) is a rare skeletal dysplasia inherited as an autosomal recessive trait, which is caused by mutations in RMRP and allelic to a more common disorder, cartilage hair hypoplasia (CHH). CHH is a multi-system disorder with a variety of extraskeletal changes. Whereas AAD is a bone-restricted disorder with a more severe skeletal phenotype: affected individuals are extremely short and complicated by orthopedic morbidity, and the radiological changes include modification of the vertebral bodies and epiphyseal dysplasia of the hip, as well as generalized metaphyseal dysplasia and severe brachydactyly. Recently, genetic heterogeneity for AAD was proposed, because a familial case (two affected sibs) with an AAD-identical phenotype had compound heterozygous mutations in POP1, encoding a molecule functionally related to the gene product of RMRP. We report here a 5-year-old boy with the same phenotype born to a consanguineous couple. We identified a novel homozygous POP1 mutation (c.1744C>T, p.P582S) in the boy and the heterozygosity in the parents. It may be rational to coin the POP1-associated skeletal phenotype AAD type 2. © 2016 Wiley Periodicals, Inc.
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Proteínas Reguladoras de la Apoptosis/genética , Enanismo/diagnóstico , Enanismo/genética , Estudios de Asociación Genética , Mutación , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Fenotipo , Ribonucleoproteínas/genética , Alelos , Preescolar , Biología Computacional/métodos , Consanguinidad , Análisis Mutacional de ADN , Exones , Homocigoto , Humanos , Masculino , RadiografíaRESUMEN
Spondylo-meta-epiphyseal dysplasia (SMED), short limb-abnormal calcification type (SMED, SL-AC), is a very rare autosomal recessive disorder with various skeletal changes characterized by premature calcification leading to severe disproportionate short stature. Twenty-two patients have been reported until now, but only five mutations (four missense and one splice-site) in the conserved sequence encoding the tyrosine kinase domain of the DDR2 gene has been identified. We report here a novel DDR2 missense mutation, c.370C > T (p.Arg124Trp) in a Moroccan girl with SMED, SL-AC, identified by whole exome sequencing. Our study has expanded the mutational spectrum of this rare disease and it has shown that exome sequencing is a powerful and cost-effective tool for the diagnosis of clinically heterogeneous disorders such as SMED.
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Calcinosis/genética , Calcinosis/patología , Enanismo/genética , Enanismo/patología , Exoma/genética , Mutación Missense/genética , Osteocondrodisplasias/genética , Osteocondrodisplasias/patología , Proteínas Tirosina Quinasas Receptoras/genética , Receptores Mitogénicos/genética , Preescolar , Receptores con Dominio Discoidina , Femenino , Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , MarruecosRESUMEN
Background: Focal dermal hypoplasia (Goltz syndrome) is a genetic multisystem disorder characterized primarily by involvement of the skin associated to face, skeletal, and eyes anomalies. The objective of the present series is to shed light on this rare syndrome and these atypical manifestations. Methodology: Our study reports the case of five Moroccan patients who present typical clinical picture of the Goltz syndrome with some rare manifestations. Results: A total of 5 patients with Goltz syndrome were evaluated. All of them are female with one familial case. The age ranged from 8 months to 35 years. A characteristic Blaschkoid hypo- and hyper-pigmented skin lesions, congenital nodular fat herniation, and skin atrophy were present in all patients. Ocular manifestations were present in 80% of patients. Cranio-facial deformity was seen in 80% of patients. Short stature and intellectual delay were documented in 80% and 40% of patients, respectively. Limb abnormality was found in all patients. Two patients had a cleft lip, one of which unusual lateral facial cleft. Limitations: Genetic testing could not be performed in the present series. Conclusions: Through this work we will discuss the different clinical signs and genetic aspects of Goltz syndrome and the interest of a good clinical expertise.
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The objective of this work was to identify phenotypic features and cytogenetic aspects of trisomy 13 in Moroccan population. The retrospective study was conducted on a group of 9 cases diagnosed cytogenetically with trisomy 13. The study of sex ratio showed a slight female dominance in our group of cases. The major clinical findings included: Holoprosencephaly, microphthalmia and anophthalmia, coloboma of iris, cleft lip and palate, nasal and ear abnormalities, retrognathism and sloping forehead, polydactyly, capillary hemangiomas, omphalocele, congenital heart defect, renal abnormalities, cryptorchidism, language delay. The cytogenetic study showed the dominance of the free and homogeneous trisomy 13 (56%). Patients who have this formula are dead at an early age (does not exceed one month). However, each of the chromosomal formula, trisomy 13 by translocation and partial trisomy 13 t (13;18), was found in 20% of our patients. The partial trisomy 13 t (13;18) is the only variant that is still alive and the patients with this anomaly suffer mainly from renal and cardiac anomalies with slight dysmorphia and psychomotor retardation. Our study shows the interest of the cytogenetic analysis in the diagnosis accuracy and in the genetic counseling of patients with Patau syndrome and their parents.
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Anomalías Múltiples , Fenotipo , Síndrome de la Trisomía 13 , Humanos , Femenino , Masculino , Marruecos/epidemiología , Estudios Retrospectivos , Síndrome de la Trisomía 13/genética , Anomalías Múltiples/genética , Anomalías Múltiples/epidemiología , Lactante , Análisis Citogenético , Recién Nacido , Trisomía/genética , Trastornos de los Cromosomas/genética , Trastornos de los Cromosomas/epidemiología , Trastornos de los Cromosomas/diagnóstico , Cromosomas Humanos Par 13/genética , PreescolarRESUMEN
Spinocerebellar ataxia type 7 (SCA7) is a rare autosomal dominant neurodegenerative disease. Its clinical presentation is a progressive cerebellar ataxia associated with cone and retinal dystrophy. The CAG repeat expansion in the ataxin-7 gene (ATXN7) causes spinocerebellar ataxia type 7 - a mutation that results in the degeneration of the brain stem cells, retina and cerebellum. We report in this study the clinical and genetic features of a new Moroccan family of SCA7, from the South of Morocco. We performed the molecular genetic testing to confirm the diagnosis of SCA7. The objective of this study is to report a new Moroccan case of SCA7 and to illustrate the role of the geneticist in the diagnosis, management and development of genetic counseling of SCA7 disease.
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Ataxina-7/genética , Ataxias Espinocerebelosas/diagnóstico , Adolescente , Adulto , Femenino , Pruebas Genéticas , Humanos , Masculino , Marruecos , Mutación , Ataxias Espinocerebelosas/genética , Ataxias Espinocerebelosas/fisiopatología , Adulto JovenRESUMEN
The 1p36 deletion syndrome results from a heterozygous deletion of the terminal chromosomal band of the short arm of chromosome 1. Monosomy 1p36 is the most common terminal deletion observed in men (1 in 5000 newborns), characterized by distinctive dysmorphia, delayed growth, psychomotor retardation, intellectual deficit, epilepsy and heart defects. Fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH-array) are currently the two best diagnostic techniques. The objective of this work is to take stock of the first Moroccan case of 1p36 deletion and to illustrate the role of the geneticist in the diagnosis and management of this syndrome. There is currently no effective medical treatment for this disease.
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Trastornos de los Cromosomas/diagnóstico , Hibridación Fluorescente in Situ , Preescolar , Deleción Cromosómica , Trastornos de los Cromosomas/fisiopatología , Cromosomas Humanos Par 1 , Hibridación Genómica Comparativa , Femenino , Humanos , MarruecosRESUMEN
Diabetic nephropathy (DN) is one of the severe complications of Type-2 diabetes mellitus (T2DM) and a major cause of end-stage renal disease in these patients. Results from published studies on the relationship between angiotensin-converting enzyme (ACE) insertion/ deletion (I/D) gene polymorphism and patients with DN are still conflicting. We compared the clinical characteristics and the genotype frequencies of ACE polymorphism in 130 T2DM Moroccan patients with DN and 85 T2DM Moroccan patients without DN (controls) using specific primers in a polymerase chain reaction. The degenerative complications of diabetes were significantly higher in the group with nephropathy. The distribution of the I/D genotypes was in Hardy-Weinberg equilibrium. The D allele was the most frequent allele in the Moroccan population in both groups studied (P = 0.68), however, there was no significant difference between the genotypes in T2DM patients with or without DN (P = 0.78). The ACE gene I/D polymorphism was not associated with an increased risk of DN in the Moroccan population.
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Diabetes Mellitus Tipo 2/genética , Mutación INDEL , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Anciano , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Marruecos/epidemiología , Fenotipo , Estudios Prospectivos , Factores de RiesgoRESUMEN
Pediatric cardiomyopathy is a rare but severe disease with high morbidity and mortality. The causes are poorly understood and can only be established in one-third of cases. Recent advances in genetic technologies, specifically next-generation sequencing, now allow for the detection of genetic causes of cardiomyopathy in a systematic and unbiased manner. This is particularly important given the large clinical variability among pediatric cardiomyopathy patients and the large number of genes (>100) implicated in the disorder. We report on the performance of whole-exome sequencing in members of a consanguineous family with a history of pediatric hypertrophic cardiomyopathy and sudden cardiac death, which led to the identification of a homozygous stop variant in the SLC22A5 gene, implicated in primary carnitine deficiency, as the likely genetic cause. Targeted carnitine tandem mass spectrometry analysis in the patient revealed complete absence of plasma-free carnitine and only trace levels of total carnitine, further supporting the causality of the SLC22A5 variant. l-carnitine supplementation in the proband led to a rapid and marked clinical improvement. This case illustrates the use of exome sequencing as a systematic and unbiased diagnostic tool in pediatric cardiomyopathy, providing an efficient route to the identification of the underlying cause, which lead to appropriate treatment and prevention of premature death.
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Cardiomiopatías/genética , Carnitina/deficiencia , Codón de Terminación/genética , Proteínas de Transporte de Catión Orgánico/genética , Adulto , Cardiomiopatías/diagnóstico , Cardiomiopatías/tratamiento farmacológico , Carnitina/sangre , Carnitina/uso terapéutico , Muerte Súbita , Exoma , Femenino , Humanos , Lactante , Masculino , Mutación , Linaje , Miembro 5 de la Familia 22 de Transportadores de SolutosRESUMEN
INTRODUCTION: Joubert syndrome is a rare congenital disorder characterized by brain malformation, developmental delay with hypotonia, ocular motor apraxia, and breathing abnormalities. Joubert syndrome is a genetically highly heterogeneous ciliopathy disorder with 23 identified causative genes. The diagnosis is based on brain imaging showing the "molar tooth sign" with cerebellar vermis agenesis. We describe a consanguineous Moroccan family with three affected siblings (18-year-old boy, 13-year-old girl, and 10-year-old boy) showing typical signs of Joubert syndrome, and attempt to identify the underlying genetic defect in this family. METHODS: We performed genome-wide homozygosity mapping using a high-resolution array followed by targeted Sanger sequencing to identify the causative gene. RESULTS: This approach found three homozygous regions, one including the AHI1 gene. Direct sequencing of the 26 coding exons of AHI1 revealed a homozygous mutation (p.Thr304AsnfsX6) located in exon 7 present in the three Joubert syndrome-affected Moroccan siblings. Of more interest, this truncating mutation was previously reported in patients with compound heterozygous Joubert syndrome originating from Spain (one patient) and from the Netherlands (two patients), suggesting a possible founder effect or mutational hotspot. CONCLUSIONS: Combined homozygosity mapping and targeted sequencing allowed the rapid detection of the disease-causing mutation in the AHI1 gene in this family affected with a highly genetically heterogeneous disorder. Carriers of the same truncating mutation (p.Thr304AsnfsX6), originating from Spain and the Netherlands, presented variable clinical characteristics, thereby corroborating the extreme heterogeneity of Joubert syndrome.
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Proteínas Adaptadoras Transductoras de Señales/genética , Enfermedades Cerebelosas/genética , Cerebelo/anomalías , Retina/anomalías , Anomalías Múltiples/genética , Proteínas Adaptadoras del Transporte Vesicular , Adolescente , Niño , Anomalías del Ojo/genética , Femenino , Heterocigoto , Humanos , Enfermedades Renales Quísticas/genética , Imagen por Resonancia Magnética , Masculino , Marruecos , Mutación , LinajeRESUMEN
BACKGROUND: Congenital insensitivity to pain is a rare autosomal recessive disease. Individuals who are diagnosed with congenital insensitivity to pain usually present severely impaired pain perception, and in some cases, they also manifest a decreased sense of smell (anosmia). This disease is caused by loss of function mutations affecting the SCN9A gene, which encodes the voltage-gated sodium channel Nav1.7. It is noteworthy that nearly every mutation linking this particular channel to congenital insensitivity to pain has been demonstrated to underlie the translation of a truncated protein. METHODS: Complete sequencing of the SCN9A gene in a Moroccan 3-year-old child with congenital insensitivity to pain. RESULT: We identified a homozygous nonsense mutation (c.4795C>T) in exon 27, that results in codon stop in the amino acid (p.R1599X). CONCLUSION: In this report we present a previously unreported homozygous nonsense mutation present in a consanguineous Moroccan congenital insensitivity to pain patient with anosmia. The identification of this mutation extends the spectrum of mutations affecting the Nav1.7 channel, and it confirms earlier studies that established Nav1.7 roles in nociception and the sense of smell.