Genetic Diagnosis of Inborn Errors of Immunity in an Emerging Country: a Retrospective Study of 216 Moroccan Patients.

PURPOSE: Genetic testing provides great support to validate the clinical diagnosis of inborn errors of immunity (IEI). However, the high cost and advanced technology make these tests inaccessible to a large proportion of patients in low-income countries. In the present study, we aim to evaluate the Moroccan experience in genetic testing and to report the main molecular features and difficulties encountered in genetic diagnosis. METHODS: We performed a multi-center retrospective analysis of all patients with a molecular diagnosis and registered in the national registry between 2010 and 2022. To estimate the impact of the newly identified mutations, we calculated the Combined Annotation Dependent Depletion (CADD) score and the mutation significance cutoff (MSC) for each variant. RESULTS: A total of 216 (29%) patients received a genetic diagnosis out of 742 patients with IEI included in the registry. All genetic tests were performed in the context of thesis projects (40%) or international collaborations (60%). A set of 55 genetic defects were identified, including 7 newly reported: SNORA31, TBX21, SPPL2A, TYK2, RLTPR, ZNF341, and STAT2 GOF. Genetic diagnoses were more frequent in the defects of innate and intrinsic immunity with a percentage of 78%, while antibody deficiencies had a lower frequency with a percentage of 17.5%. Only one genetic diagnosis has been made in the complement deficiency group. The most commonly used molecular techniques were Sanger sequencing (37%) followed by targeted gene sequencing (31%). CONCLUSION: The thesis projects and collaborations were beneficial as they allowed us to provide a definitive genetic diagnosis to 29% of the patients and to contribute to the identification of new genetic defects and mutations. These results offer insight into the progress made in genetic diagnoses of IEI in Morocco, which would provide a baseline for improving the clinical management of patients with IEI.

Clinical and Immunological Features of 96 Moroccan Children with SCID Phenotype: Two Decades' Experience.

Severe combined immunodeficiency (SCID) is a heterogeneous group of primary immunodeficiency diseases (PIDs) characterized by a lack of autologous T lymphocytes. This severe PID is rare, but has a higher prevalence in populations with high rates of consanguinity. The epidemiological, clinical, and immunological features of SCIDs in Moroccan patients have never been reported. The aim of this study was to provide a clinical and immunological description of SCID in Morocco and to assess changes in the care of SCID patients over time. This cross-sectional retrospective study included 96 Moroccan patients referred to the national PID reference center at Casablanca Children's Hospital for SCID over two decades, from 1998 to 2019. The case definition for this study was age < 2 years, with a clinical phenotype suggestive of SCID, and lymphopenia, with very low numbers of autologous T cells, according to the IUIS Inborn Errors of Immunity classification. Our sample included 50 male patients, and 66% of the patients were born to consanguineous parents. The median age at onset and diagnosis were 3.3 and 6.5 months, respectively. The clinical manifestations commonly observed in these patients were recurrent respiratory tract infection (82%), chronic diarrhea (69%), oral candidiasis (61%), and failure to thrive (65%). The distribution of SCID phenotypes was as follows: T-B-NK+ in 44.5%, T-B-NK- in 32%, T-B+NK- in 18.5%, and T-B+NK+ in 5%. An Omenn syndrome phenotype was observed in 15 patients. SCID was fatal in 84% in the patients in our cohort, due to the difficulties involved in obtaining urgent access to hematopoietic stem cell transplantation, which, nevertheless, saved 16% of the patients. The autosomal recessive forms of the clinical and immunological phenotypes of SCID, including the T-B-NK+ phenotype in particular, were more frequent than those in Western countries. A marked improvement in the early detection of SCID cases over the last decade was noted. Despite recent progress in SCID diagnosis, additional efforts are required, for genetic confirmation and particularly for HSCT.

X-Linked Agammagobulinemia in a Large Series of North African Patients: Frequency, Clinical Features and Novel BTK Mutations.

PURPOSE: X-linked agammagobulinemia (XLA) is a primary immunodeficiency caused by Bruton's tyrosine kinase (BTK) gene defect. XLA patients have absent or reduced number of peripheral B cells and a profound deficiency in all immunoglobulin isotypes. This multicenter study reports the clinical, immunological and molecular features of Bruton's disease in 40 North African male patients. METHODS: Fifty male out of 63 (male and female) patients diagnosed with serum agammaglobulinemia and non detectable to less than 2% peripheral B cells were enrolled. The search for BTK gene mutations was performed for all of them by genomic DNA amplification and Sanger sequencing. RESULTS: We identified 33 different mutations in the BTK gene in 40 patients including 12 missense mutations, 6 nonsense mutations, 6 splice-site mutations, 5 frameshift, 2 large deletions, one complex mutation and one in-frame deletion. Seventeen of these mutations are novel. This large series shows a lower frequency of XLA among male patients from North Africa with agammaglobulinemia and absent to low B cells compared with other international studies (63.5% vs. 85%). No strong evidence for genotype-phenotype correlation was observed. CONCLUSIONS: This study adds to other reports from highly consanguineous North African populations, showing lower frequency of X-linked forms as compared to AR forms of the same primary immunodeficiency. Furthermore, a large number of novel BTK mutations were identified and could further help identify carriers for genetic counseling.

Neonatal hyperekplexia with homozygous p.R392H mutation in GLRA1.

Hyperekplexia is a rare neurogenetic disorder, frequently misdiagnosed in neonates with a risk of apnoea, asphyxia, and sudden infant death. We present video sequences of a male newborn, admitted on the second day of life to the neonatal intensive care unit, due to tonic-clonic movements. Following clinical and paraclinical investigations, a final diagnosis of hyperekplexia was made. Genetic analysis revealed a homozygous mutation in GLRA1 resulting in a R392H amino acid substitution and altered receptor dynamics, as indicated from previous work. The infant showed a marked improvement of the startle response and muscle hypertonia with clonazepam which is a strong clinical feature of GLRA1-mediated hyperekplexia. [Published with video sequences].

[Niemann Pick disease A: a case report]. / Maladie de Niemann Pick type A : à propos d'un cas.

The Niemann Pick disease is a rare lysosomal storage disease responsible for numerous cytological abnormalities of blood cells and bone marrow. The diagnosis requires enzymatic dosages, which can be long and difficult. In this context, the detection of inconstant cytologic anomalies in blood and bone marrow smears, allowing a rapid screening, is an important step in the diagnostic approach. We report the case of a 6 year-old child who presents with abdominal distension; medullogram was performed and revealed the presence of vacuolated cells overload. Correlated with clinical and biochemical data, medullogam results confirmed the diagnosis of type A Niemann Pick disease.

[Fanconi anemia at the University Hospital (CHU) Hassan II of Fez: about 6 cases]. / Anémie de fanconi au CHU Hassan II Fès: à propos de 6 observations.

Fanconi anemia is a recessive disorder associated with chromosomal instability. It is marked by phenotypical heterogeneity which includes medullary deficiency, a variable malformation syndrome, a predisposition to develop acute leukaemias myéloïdes (ALM) and a cellular over-sensitiveness with the agents bridging the ADN. The diagnosis is based on the abnormal increase in the rate of spontaneous breaks chromosomal but especially and in a specific way, on a clear increase in these chromosomal breaks in the presence of bifunctional alkylating agents, which is the case in our six patients. Genetic counseling is that available for autosomal recessive diseases. We report our initial observations conducted at the University Hospital (CHU) Hassan II of Fez confirmed by the detection of a large chromosomal instability after culture with Mitomycin C compared to a normal control group. The purpose of this study was to update our knowledge of Fanconi anemia genes and to highlight the role of cytogenetics in its diagnosis and the genetic counseling for better management of affected children and their families.

The detection of a novel insertion mutation in exon 2 of the MEFV gene associated with familial mediterranean fever in a moroccan family.

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease that is inherited in an autosomal recessive manner and is caused by mutations in the MEFV gene. As the name indicates, FMF occurs within families and is more common in individuals of Mediterranean descent than in persons of any other ethnicity. To date, 314 mutations have been reported. We studied a Moroccan family with a total of five members, including a mother who was presenting with symptoms of FMF, while her four children remained asymptomatic. The five patients were screened by DNA sequencing of exon 2 and exon 10 of the MEFV gene. Then, complete exome sequencing analysis of the MEFV gene was done for the patients in whom a novel mutation was detected. This analysis identified a novel single base Cytosine (C) insertion mutation in the coding region of the MEFV gene, named c.441dupC (p. Glu148Argfs*5 or E148RfsX5), which resulted in a mutated Pyrin/Marenostrin protein. This is the first report of a new mutation in exon 2 of the MEFV gene in a Moroccan family. This novel insertion mutation may provide important information for further studies of FMF pathogenesis.

A rare tumor of the lung: inflammatory myofibroblastic tumor.

Inflammatory myofibroblastic tumor is a rare benign lesion whose tumor origin is now proven. It represents 0.7% of all lung tumors. We report the case of a three-year-old child who suffered from a chronic cough with recurrent respiratory infections. Chest X-ray and computed tomography revealed the presence of a left lower lobe lung mass. After pneumonectomy, histological examination combined with immunohistochemical study discovered an inflammatory myofibroblastic tumor.The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8722069326962972.

Congenital insensitivity to pain with anhydrosis: report of a family case.

Congenital Insensitivity to pain with anhydrosis (CIPA) is a rare inherited disease. It is classified as hereditary sensory and autonomic neuropathy type IV. Pain insensitivity and autonomic deficits are present, but touch and pressure sensitivity are unimpaired. Mental retardation is usually present. We report a family case of a 5 years old girl and 2 years old boy with congenital insensitivity to pain, while discussing the clinical features and the anesthetic strategy of such patients. Patients with Congenital Insensitivity to Pain with anhydrosis may undergo surgery because of susceptibility to trauma due to absence of pain. The clinical features may intrinsically possess anesthetic challenges.