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.

Mendelian Susceptibility to Mycobacterial Disease (MSMD): Clinical, Immunological, and Genetic Features of 22 Patients from 15 Moroccan Kindreds.

PURPOSE: The first molecular evidence of a monogenic predisposition to mycobacteria came from the study of Mendelian susceptibility to mycobacterial disease (MSMD). We aimed to study this Mendelian susceptibility to mycobacterial diseases in Moroccan kindreds through clinical, immunological, and genetic analysis. METHODS: Patients presented with clinical features of MSMD were recruited into this study. We used whole blood samples from patients and age-matched healthy controls. To measure IL-12 and IFN-γ production, samples were activated by BCG plus recombinant human IFN-γ or recombinant human IL-12. Immunological assessments and genetic analysis were also done for patients and their relatives. RESULTS: Our study involved 22 cases from 15 unrelated Moroccan kindreds. The average age at diagnosis is 4 years. Fourteen patients (64%) were born to consanguineous parents. All patients were vaccinated with the BCG vaccine, and twelve of them (55%) developed locoregional or disseminated BCG infections. The other symptomatic patients had severe tuberculosis and/or recurrent salmonellosis. Genetic mutations were identified on the following genes: IL12RB1 in 8 patients, STAT1 in 7 patients; SPPL2A, IFNGR1, and TYK2 in two patients each; and TBX21 in one patient, with different modes of inheritance. All identified mutations/variants altered production or response to IFN-γ or both. CONCLUSION: Severe forms of tuberculosis and complications of BCG vaccination may imply a genetic predisposition present in the Moroccan population. In the presence of these infections, systematic genetic studies became necessary. BCG vaccination is contraindicated in MSMD patients and should be delayed in newborn siblings until the exclusion of a genetic predisposition to mycobacteria.

Implementing the WHO Global Initiative for Childhood Cancer in Morocco: Survival study for the six indexed childhood cancers.

BACKGROUND: In 2018, the World Health Organization (WHO) launched the Global Initiative for Childhood Cancer (GICC). The goal is to achieve a global survival rate of at least 60% for all children with cancer by 2030. Morocco was designated as a pilot country for this initiative. PROCEDURE: This retrospective study included a cohort of children aged 0-15 years, with one of the six indexed cancers (acute lymphoblastic leukemia [ALL], Burkitt lymphoma [BL], Hodgkin lymphoma, retinoblastoma [RB], Wilms tumor or nephroblastoma, low-grade glioma), diagnosed between January 1, 2017 and December 31, 2019 at the six Moroccan Pediatric Hematology and Oncology units. Patients were followed-up until August 31, 2020. The Kaplan-Meier method was used to estimate survival rates, the log-rank test for comparing survival curves, and the Cox model for identifying prognostic factors. RESULTS: Data on 878 patients were included in the study. The most frequently reported cancer type was ALL (n = 383, 43.6%), followed by Wilms tumor (n = 139, 15.8%) and BL (n = 133, 15%). Most patients were less than 5 years of age (n = 446, 50.9%) and the male/female ratio was 1.46. The 1, 2, and 3-year overall survival rates were 80.1%, 73.6%, and 68.2%, respectively. In a multivariable Cox regression model, care center, cancer type, age group, and distance to the care center were statistically significantly associated to survival. Patients aged 10 years and older and patients living more than 100 km from the care center were more likely to die (respectively, HR = 1.39, p = .045 and HR = 1.44, p = .010). CONCLUSION: The reported results represent the baseline for measuring the impact of GICC implementation in Morocco.

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.

Chronic granulomatous disease in Morocco: genetic, immunological, and clinical features of 12 patients from 10 kindreds.

PURPOSE: Chronic granulomatous disease (CGD) is characterized by an inability of phagocytes to produce reactive oxygen species (ROS), which are required to kill some microorganisms. CGD patients are known to suffer from recurrent bacterial and/or fungal infections from the first year of life onwards. From 2009 to 2013, 12 cases of CGD were diagnosed in Morocco. We describe here these Moroccan cases of CGD. METHODS: We investigated the genetic, immunological and clinical features of 12 Moroccan patients with CGD from 10 unrelated kindreds. RESULTS: All patients were children suffering from recurrent bacterial and/or fungal infections. All cases displayed impaired NADPH oxidase activity in nitroblue tetrazolium (NBT), dihydrorhodamine (DHR) or 2',7' dichlorofluorescein diacetate (DCFH-DA) assays. Mutation analysis revealed the presence of four different mutations of CYBB in four kindreds, a recurrent mutation of NCF1 in three kindreds, and a new mutation of NCF2 in three patients from a single kindred. A large deletion of CYBB gene has detected in a patient. The causal mutation in the remaining one kindred was not identified. CONCLUSION: The clinical features and infectious agents found in these patients were similar to those in CGD patients from elsewhere. The results of mutation analysis differed between kindreds, revealing a high level of genetic and allelic heterogeneity among Moroccan CGD patients. The small number of patients in our cohort probably reflects a lack of awareness of physicians. Further studies on a large cohort are required to determine the incidence and prevalence of the disease, and to improve the description of the genetic and clinical features of CGD patients in Morocco.

Christ-Siemens-Touraine Syndrome: A Report of a Rare Pediatric Case.

Anhidrotic ectodermal dysplasia (AED), or Christ-Siemens-Touraine syndrome, is an X-linked recessive dermatosis. Rare in incidence, it affects 1 in 100,000 births, mostly boys. Through this observation, we detail the clinical signs that led us to suspect the diagnosis, how this pathology was confirmed, and the therapeutic management we carried out. We present a case of a 10-month-old boy presenting with altered manifestations affecting almost all the ectodermal structures like skin, hair, nails, teeth, sebaceous glands, sweat glands, and tear glands. He also had complete anodontia and a dry mouth. A multidisciplinary treatment was given to the patient with the collaboration of various health professionals. Although Christ-Siemens-Touraine syndrome is a rare condition, it is vital to recognize it early to improve care and prognosis for these patients, while mitigating the psychological impact of the condition on both children and parents.

A rare case of steroid 11 beta-hydroxylase deficiency in a child revealed by acute pulmonary edema.

We report the case of a 5-year-old boy diagnosed with congenital adrenal hyperplasia due to 11-hydroxylase deficiency, revealed by disorders of sex development (DSD) and acute pulmonary edema due to severe hypertension. We considered the diagnosis based on biological and radiological examinations. The sociocultural background and the delayed diagnosis had a significant impact on the therapeutic decisions. All babies should be screened for 11 beta-hydroxylase deficiency, there should be specialized and interdisciplinary medical centers, and early detection is essential to avoiding serious complications of this disease.

Albinism and Primary Immunodeficiency in Infants: A Case Study of Griscelli Syndrome.

Griscelli syndrome (GS) type II is a rare hereditary disorder characterized by partial albinism, immunodeficiency, and the subsequent development of hemophagocytic syndrome (HPS). Herein, we present a case involving a four-month-old infant admitted to our facility due to a prolonged fever complicated by HPS. The diagnosis of GS type 2 was established based on a constellation of clinical and laboratory findings: consanguinity, familial history of early infectious fatalities, ocular-cutaneous hypopigmentation, characteristic silvery hair sheen, onset of HPS, and notably, the pathognomonic appearance upon microscopic examination of a hair sample. The absence of giant granules within nucleated cells helped exclude Chediak-Higashi syndrome.

Exceptional case of a hemangioma-like rabdomyosarcoma in the hand's palm.

Rhabdomyosarcoma is a malignant tumor in children that might mimic a benign tumor, such as infantile hemangioma, particularly when detected early. Although rhabdomyosarcoma rarely occurs in the hand, its prognosis is generally poor, and successful treatment relies on a complete and radical surgical excision. We present a case of rhabdomyosarcoma located in the palm of an infant's hand, initially presenting clinical and radiological features suggestive of a vascular tumor. The resection of this mass was radical, and histological analysis and immunohistochemistry returned in favor of embryonic rhabdomyosarcoma. In similar cases recorded in the literature, the diagnosis may be first mistaken for that of a hemangioma, then confirmed by histology. This underlines the importance of a systematic anatomopathological examination of all tissues removed surgically.

Triple-A Syndrome in Morocco: Founder Effect, Age Estimation of the AAAS c.1331+1G>A Variant, and Implications for Genetic Diagnosis.

Introduction: Triple-A syndrome (Triple-A) is an autosomal recessive disorder characterized by alacrimia, achalasia, and adrenal insufficiency. Several variants on the AAAS gene have been described, and some variants are clustered in particular geographical areas, such as the c.1331+1G>A variant which is very frequent in North Africa. Here, we describe the genetic features of Triple-A in a series of unrelated families from Morocco. Methods: Screening for the AAAS c.1331+1G>A variant was performed by direct sequencing or by PCR-RFLP. Haplotype analysis using Single Tandem Repeat (STR) markers flanking AAAS gene was performed in order to evaluate the founder effect and estimate the age of the c.1331+1G>A variant. Results: Seven unrelated families with ten individuals clinically diagnosed with Triple-A were evaluated for sequence variations in the AAAS gene. The median age at diagnosis was 3 years, with a range between 2 and 11 years. Molecular analysis revealed that all patients were homozygous for the c.1331+1G>A variant. This variant was not found in 200 healthy controls, indicating that carriers are very rare in the general Moroccan population. Subsequently, STR marker analysis revealed a founder effect and that the most recent common ancestor of Triple-A patients in Morocco would have lived 125 years ago. Conclusion: This is the largest series of Triple-A in Morocco. The same AAAS c.1331+1G>A variant was found in all patients, suggesting a founder effect in Morocco which was subsequently confirmed by microsatellite marker analysis. Therefore, this variant should be systematically investigated to diagnose Triple-A in Morocco.

First report on chromosomal abnormalities in Eastern Morocco: Identification of a new case of a de novo partial trisomy 13q using single-nucleotide polymorphism array.

BACKGROUND: Chromosomal abnormalities are the main cause of birth defects, intellectual disability, and miscarriages. They contribute to significant human morbidity and infant mortality. Here we report for the first time the chromosomal abnormalities encountered in the population of Eastern Morocco. Furthermore, we describe a new case of a de novo partial trisomy 13q combined with a terminal deletion in an 11-day-old girl. METHODS: From November 2015 to March 2022, 195 patients from the BRO Biobank who were clinically suspected of having chromosomal abnormalities were referred to the cytogenetics laboratory of the Genetics Unit of the Faculty of Medicine and Pharmacy of Oujda for cytogenetic study. Karyotyping analysis was performed on peripheral blood samples using standard R banding techniques. To identify single-nucleotide polymorphism (SNP) and copy number variants (CNVs), Illumina SNP array was used. RESULTS: Among 195 studied cases, 32 (16.4 %) had abnormal karyotypes, of which 12 cases had numerical aberrations while 20 cases had structural aberrations. The most common numerical aberrations were Turner syndrome and Down syndrome followed by Edward, Patau, and Klinefelter syndromes. For structural aberrations, translocations were the most common, followed by derivative chromosomes, inversions, deletions, and an addition on chromosome 13 identified in an 11-day-old girl. To further characterize this addition, SNP array was carried out and revealed a 58.8-Mb duplication in region 13q14.3q34 associated with a 1-Mb deletion in region 13q34. Follow-up parental chromosomes analysis showed normal karyotypes for the parents, confirming that this partial trisomy 13q was de novo. Comparison of the phenotype associated with this novel duplication on chromosome 13q with those previously reported confirmed the considerable variability in the phenotype of the patients with partial trisomy 13q. CONCLUSION: This study provided the first report on chromosomal abnormalities in Eastern Morocco and it enriched the phenotype spectrum of partial trisomy 13q and further confirmed the genotype-phenotype correlations. Furthermore, these findings justify the need to set up microarray comparative genomic hybridization techniques in Morocco for better genetic diagnosis.

Chronic renal failure revealing a spinal arachnoid cyst, a case report with literature review.

INTRODUCTION: Extradural arachnoid cyst (KAED) is a rare and benign condition, accounting for approximately 1 % of all spinal expansive lesions. The pathogenesis of KAED is uncertain and appears to be multifactorial. Spinal compression symptoms are rarely indicative, and KAED is usually discovered incidentally. MRI is the radiological test of choice as it allows for precise characterization of the cyst. Early identification and management of KAED is crucial to prevent complications and ensure timely intervention. CASE PRESENTATION: A 7-year-old girl with a nomadic lifestyle presented with sphincterian disorders without any other neurological abnormalities. Further investigation, including biological tests, revealed chronic kidney failure. A spinal MRI identified an intra-spinal extradural dorso-lumbar arachnoid cyst extending from D10 to L1, located posteriorly. The cyst was promptly removed with favorable postoperative outcomes. The patient was discharged with a treatment of vitaminocalcic and martial supplementation for his chronic renal insufficiency and a regular follow-up in consultation. CLINICAL DISCUSSION: Arachnoid cyst is a rare benign condition that can be discovered incidentally (Agnoli et al., 1982; Chan et al.; 1985). The symptoms are the results of compression exerted by the cyst on the cord and they vary according to the level of compression of the spinal cord or the nerve roots, but the symptomatic form is a situation which remains rarely described (Charisseauj et al., 1992). In this particular case, the cyst was identified due to a series of symptoms related to acute renal insufficiency, which exacerbated pre-existing chronic renal insufficiency. This was further complicating untreated sphincter disorders. This highlights the significance of timely diagnosis and treatment to prevent severe complications that may otherwise develop from a benign condition. With early intervention, favorable outcomes can be achieved in most patients (Kendall et al., 1982). CONCLUSION: With the advancement of neuroimaging and the widespread availability of MRI as the gold standard, extradural arachnoid cysts (KAED) can now be incidentally discovered in asymptomatic patients. Once diagnosed, surgical intervention is typically recommended to prevent irreversible neurological damage. Further research is needed to better understand the pathogenesis of KAED and establish optimal diagnosis and treatment strategies, particularly in pediatric patients, for this rare condition.

Corrigendum to Acute pancreatitis following L-asparaginase in acute lymphoblastic leukemia.

[This corrects the article DOI: 10.1016/j.lrr.2022.100357.].

A very rare case of bacteraemia in a 4-year-old girl with osteopetrosis with probable Leuconostoc lactis infection.

Leuconostoc lactis (LLac) is a Gram-positive coccus of the family Leuconostocaceae . It can be found in a variety of vegetables and dairy products. LLac is an opportunistic pathogen with intrinsic resistance to vancomycin and teicoplanin. In this case report, we discuss a rare case of LLac-associated bacteraemia in a patient with osteopetrosis. A 4-year-old girl was admitted to the paediatric emergency department with acute fever without other signs. Blood culture revealed an infection with LLac. Using the streptococcus antibiogram, the isolate was resistant to vancomycin, teicoplanin, rifampicin and sulfamethoxazole-trimethoprim but sensitive to ß-lactams, gentamicin, streptomycin, azithromycin, clarithromycin, lincomycin, clindamycin and erythromycin. The patient was treated with intravenous ceftriaxone and gentamicin, and subsequently with oral amoxicillin. After a favourable course, she was discharged from the hospital on the 10th day. The modes of transmission and physiopathology of LLac remain unknown. Factors associated with this infection include compromised immunity, previous antibiotic therapy especially with vancomycin, and application of a central venous catheter. In our patient, the risk factors for infection were pancytopenia and multiple transfusions used to treat bone marrow failure. The source of the bacteraemia could have been the cutaneous route, but it could also have been digestive due to the reservoir of the bacteria. LLac is known as an opportunistic bacterium. Further studies on its pathogenesis and other risk factors are needed to understand the true prevalence of this potentially fatal bacterium in compromised individuals, such as the case of our patient.

Malignant Rhabdoid Tumor of the Kidney in a Child With Xeroderma Pigmentosum: Incidence or Coincidence?

Malignant rhabdoid tumor of the kidney (MRTK) is a rare aggressive malignant rhabdoid tumor that mainly affects children. At the onset of the disease, the usual clinical manifestations are gross hematuria, abdominal pain, and abdominal distension. The prognosis remains poor. Patients with rhabdoid tumors (RT) are treated according to institutional preferences that combine surgery, radiation therapy, and chemotherapy. The authors present the rare case of a child with xeroderma pigmentosum (XP) who presented with an abdominal mass accompanied by hematuria and abdominal pain. The radiological and histological results were congruent with the MRTK. The patient received preoperative chemotherapy but unfortunately died of septic shock. This case highlights the importance of being aware of MRTK and its fatal complications, as well as the increased risk of kidney tumors in patients with XP.

Bean Syndrome in a Child Treated with Sirolimus: About a Case.

Bean syndrome (BS) or blue rubber bleb nevus syndrome is a rare clinical entity characterized by venous malformations mainly in the skin and digestive tract, whose hemorrhagic complications can be life threatening. We report a case of Bean syndrome in a 3-year-old child of nonconsanguineous parents, in whom the diagnosis of miliary hemangiomatosis was initially made in view of a huge mass on the left thigh, taking the knee, and then the progressive appearance of a skin disorder with bluish swellings of variable sizes spread over the whole body. The patient was put on beta-blockers but without improvement. The evolution was marked by an increase in the volume of the thigh mass. Ultrasound exploration coupled with Doppler imaging revealed the presence of angiomas in the thigh, requiring emergency surgery following a large hemorrhage. The patient underwent sclerotherapy. At the age of 18 months, the child returned with severe anemia and melena. The abdominal CT scan showed gallbladder intussusception secondary to an angioma requiring intestinal resection for hemostasis. At the age of three years, the angiomas worsened with an increase in volume, particularly on the face. The association of the cutaneous and digestive involvement of these venous malformations made us rectify the diagnosis. The patient was put on sirolimus (rapamycin), 2 mg/m2, with good evolution with a delay of 18 months; the patient presents no more episodes of bleeding with regression of the size of cutaneous angiomas. This observation underlines that BS is difficult to diagnose because of its low frequency, that sirolimus was effective and well tolerated in our patient, and that it can be suggested as a good and safe therapeutic option.

Acute pancreatitis following L-asparaginase in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most frequent malignancy in children,representing 25-30% of all childhood malignancies. Although treatment outcome has improved owing to advances in chemotherapy, there is still a group of patients who experience severe adverse events. L-Asparaginase is an effective antineoplastic agent used in chemotherapy of ALL. Despite its indisputable indication, it can cause various adverse effects, including acute pancreatitis (AP). Recently, an increase in the number of pediatric AP cases following L-Asparaginase in Acute Lymphoblastic Leukemia been reported. We presented a case of acute pancreatitis in children with ALL induced by administration of L-ASPA preparations.

What Lies Behind the Cannonball Pulmonary Metastases: Hodgkin's Lymphoma?

The cannonball pulmonary appearance is hematogenous dissemination of various primary tumors but rarely a Hodgkin's lymphoma, a disease that most commonly manifests with lymphadenopathy, often affecting the mediastinum and supraclavicular or cervical lymph nodes. To date, to the best of our knowledge, no case has been reported where the investigation of a cannonball pulmonary appearance led to the diagnosis of Hodgkin's lymphoma. Hence, in our case report, we attempt to highlight the uncommon presentation of this disease in a 14-year-old girl who initially presented with dyspnea before her chest x-ray revealed a cannonball pulmonary appearance, which was later linked with Hodgkin's lymphoma after performing a biopsy of her axillary node.

Hemiparesis Revealing a Unique Neurological Hemophagocytic Lymphohistiocytosis in a Patient With Griscelli Syndrome Type 2.

Griscelli syndrome (GS) is a rare genetic disorder that encompasses three different subtypes (GS type 1 (GS1), GS type 2 (GS2), and GS type 3 (GS3)), in which isolated neurological manifestations without immune system implications are typically seen in GS1, while neurological involvements in GS2 should be attributed to the macrophage and lymphocyte invasion of the central nervous system (CNS), under associated hemophagocytic lymphohistiocytosis (HLH). The presence of the clinical, biological, and hematologic features of HLH help explain the neurological defects that GS2 patients unusually present. In our case report, however, we attempt to highlight an uncommon presentation of GS2 involving a hemiparesis, along which we did not have any clinical or biological features of HLH. We also collect and evaluate similar published cases that feature this problem of explaining the neurological manifestations among GS2 patients.

Molecular heterogeneity of ß-thalassemia variants in the Eastern region of Morocco.

BACKGROUND: ß-thalassemia syndromes are the most common hereditary blood disorders in the world and are recognized as a major health problem in Morocco. They are characterized by the reduction or the absence of ß-globin chain synthesis. The severity of the disease depends on the nature of the variants affecting the ß-globin gene (HBB), and each ethnic group has its own mutation spectrum. Hereby, we present, for the first time, the molecular profile of ß-thalassemia in the Eastern region of Morocco. METHODS: This study concerns 39 cases from 33 families who were enrolled in the BRO Biobank. Nineteen were diagnosed with ß-thalassemia major and 20 with ß-thalassemia minor. To detect mutations of the ß-globin gene, we have used RFLP-PCR and Sanger sequencing. RESULTS: Nine known ß-thalassemia variants have been identified. Among these, we reported, for the first time in the Moroccan population, the Czechoslovakian variant C38/39(-C) at homozygous state. The C39(C > T) was the most frequent variant (72.54%), followed by FSC5(-CT) (5.88%), FSC6(-A), IVS-1-110(G > A), -29(A > G), C38/39(-C) (3.92% each), and finally by IVS-I-1(G > A), IVS-II-1(G > A), and -56(G > C) (1.96%). Of particular interest this mutational spectrum of ß-thalassemia is very different from that found in previous studies in Morocco or in other North African countries. CONCLUSION: This study is the first contribution to the description of the molecular profile of ß-thalassemia in the Eastern region of Morocco. It shows the high molecular heterogeneity of ß-thalassemia in our country. Therefore, these results can be valuable for the implementation of carrier screening, genetic counseling, and prenatal diagnosis programs.