Hemophagocytic Lymphohistiocytosis: A Rare Complication of an Ultrarare Lysosomal Storage Disease.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening hyperinflammatory condition that may be triggered by infections, autoimmune and immunologic disorders, malignancies, and metabolic diseases. Early and accurate diagnosis of HLH and its underlying cause is of paramount importance for proper management and prognosis. We report the case of a Tunisian 21-month-old girl who initially presented clinical features of HLH related to a lysosomal acid lipase deficiency. The genetic sequence analysis of the LIPA gene revealed a never described homozygous mutation c.966G>C (p.Gln322His). The parents were heterozygous for this mutation. Enzyme replacement therapy was not provided for the patient. She received etoposide, corticosteroids, and cyclosporine for the HLH. She is waiting for hematopoietic stem cell transplantation. To the best of our knowledge, this is the second Tunisian case of secondary HLH complicating lysosomal acid lipase deficiency related to a new homozygous mutation: c.966G>C (p.Gln322His).

A novel TBX1 missense mutation in patients with syndromic congenital heart defects.

Congenital heart defects represent a characteristic part of several genetic syndromes associated with chromosomal abnormalities such as 22q11.2 deletion syndrome; many genes located in this locus, mainly TBX1, are candidate genes for congenital heart defects. In our cohort of 27 subjects with congenital heart defect, both karyotype analysis and Fluorescence in situ hybridization (FISH) were performed. The TBX1 gene was sequenced in patients lacking chromosomal abnormalities. FISH analysis showed a de novo 22q11.2 deletion in two patients. The screening of TBX1 coding sequence identified a novel missense mutation c.569C > A (p.P190Q) in six unrelated patients and detected two associated known single nucleotide polymorphisms; the c.664C > T (rs2301558) in three patients and the c.420T > C (p.Phe140 Phe) (rs41298814) in one patient. Bioinformatic tools show that the novel missense mutation c.569C > A could modify the function and the stability of the TBX1 protein. The c.569C > A mutation was not found in 50 healthy controls. Ours results suggest a deleterious role of the c.569C > A mutation and strengthen the hypothesis that this mutation might be responsible for the same phenotype spectrum as the 22q11.2 deletion syndrome.

Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome.

BACKGROUND: Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease. METHODS: Clinical data were analyzed in 59 SSNS families. EMP2 gene was sequenced in families with a potential autosomal recessive (AR) inheritance. Exome sequencing was performed in a subset of 13 families with potential AR inheritance. Two variations in HLA-DQA1 were genotyped in the whole cohort. RESULTS: Transmission was compatible with an AR (n = 33) or autosomal dominant (AD, n = 26) inheritance, assuming that familial SSNS is a monogenic trait. Clinical features did not differ between AR and AD groups. All patients, including primary (n = 7) and secondary steroid resistant nephrotic syndrone (SRNS), (n = 13) were sensitive to additional immunosuppressive therapy. Both HLA-DQA1 variations were found to be highly linked to the disease (OR = 4.34 and OR = 4.89; p < 0.001). Exome sequencing did not reveal any pathogenic mutation, neither did EMP2 sequencing. CONCLUSIONS: Taken together, these results highlight the clinical and genetic heterogeneity in familial SSNS. Clinical findings sustain an immune origin in all patients, whatever the initial steroid-sensitivity. The absence of a variant shared by two families and the HLA-DQA1 variation enrichments suggest a complex mode of inheritance.

Hypoparathyroidism in children: a study of eight cases.

BACKGROUND: Hypoparathyroidism is a rare pediatric endocrine disease, which is caused by low circulating levels of PTH or insensitivity to its action in the target tissues. AIM: To report the clinical and biochemical characteristics and theoutcome of 8 patients with hypoparathyroidism. METHODS: We analyzed retrospectively the results of clinical, biochemical, radiological findings of patients with hypoparathyroidism diagnosed in pediatric department of Hedi Chaker Hospital during the period 1994-2013. RESULTS: Eight patients (5 females and 3 males) were diagnosed with hypoparathyroidism during 20 years's period. The median age at the onset of first symptoms was 17,5 months (15 days- 5 years and 10 months). Seizures were the most commonly presenting symptom and were seen in seven cases. Eight patients were diagnosed with hypoparathyroidism (Di-Georges syndrome: one case, Sanjad Sakati syndrome: 3 case, kearns sayre syndrome: 1 case, autoimmune polyendocrinopathy candidiasis- ectodermal dystrophy: one case, idiopathic hypoparathyroidism: two cases. Conventional treatment was based on calcium and vitamin D analogs. The average of follow up was 5 years. Nephrocalcinosis was noted in two patients. The death occurred in five patients; it was related to hypocalcaemia in one patient. CONCLUSION: The diagnosis of hyperparathyroidism is easy; it's established on the association of hypocalcaemia and hyperphosphatemia. Etiologic approach is based on molecular findings. Vitamin D analog treatment of hypoparathyroidism in children involves the challenge, of adjusting treatment dosage to minimize both symptomatic hypocalcemia and asymptomatic, but potentially kidney-damaging, hypercalciuria causing nephrocalcinosis and renal insufficiency.

Mutational screening in patients with profound sensorineural hearing loss and neurodevelopmental delay: Description of a novel m.3861A > C mitochondrial mutation in the MT-ND1 gene.

Mitochondrial diseases caused by mitochondrial dysfunction are a clinically and genetically, heterogeneous group of disorders involving multiple organs, particularly tissues with high-energy demand. Hearing loss is a recognized symptom of a number of mitochondrial diseases and can result from neuronal or cochlear dysfunction. The tissue affected in this pathology is most probably the cochlear hair cells, which are essential for hearing function since they are responsible for maintaining the ionic gradients necessary for sound signal transduction. Several mitochondrial DNA mutations have been associated with hearing loss and since mitochondria are crucial for the cellular energy supply in many tissues, most of these mtDNA mutations affect several tissues and will cause syndromic hearing loss. In the present study, we described 2 patients with sensorineural hearing loss and neurodevelopmental delay in whom we tested mitochondrial genes described to be associated with syndromic hearing loss. One of these patients showed a novel heteroplasmic mitochondrial mutation m.3861A > C (W185C) which lead to a loss of stability of the ND1 protein since it created a new hydrogen bund between the unique created cystein C185 and the A182 residue. In the second patient, we detected two novel heteroplasmic variations m.12350C > A (T5N) and m.14351T > C (E108G) respectively in the MT-ND5 and the MT-ND6 genes. The TopPred II prediction for the E108G variation revealed a decrease of the hydrophobicity in the mutated MT-ND6.

Report of the Tunisian Registry of Primary Immunodeficiencies: 25-Years of Experience (1988-2012).

PURPOSE: Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. METHODS: We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. RESULTS: The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. CONCLUSION: The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis.

OBJECTIVES: To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM). METHODOLOGY: Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4. RESULTS: The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%. CONCLUSION: This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Assessment of MYCN amplification status in Tunisian neuroblastoma: CISH and MLPA combining approach.

BACKGROUND: Neuroblastoma (NB) shows a complex combination of genetic aberrations. Some of them represent poor genetic prognosis factors that require specific and intensive chemotherapy. MYCN amplification consists of the major bad outcome prognostic factor, it is indeed frequently observed in aggressive neuroblastomas. To date different methods are used for MYCN status detection. OBJECTIVES: The primary aim of our study was to provide a critical assessment of MYCN status using 2 molecular techniques CISH and MLPA. We also focused on the correlation between neuroblastoma genetic markers and patient's clinical course among 15 Tunisian patients. METHODS: we developed a descriptive study that includes 15 pediatric Tunisian patients referred to our laboratory from 2004 to 2011. We reported the analysis of fresh and FFPE NB tumors tissues. RESULTS: No significant correlation was found between COG grade and patients overall survival. Assessment of NMYC gene copy number by kappa statistic test revealed high concordance between CISH and MLPA tests (kappa coefficient = 0.02). CONCLUSION: Despite misdiagnosing of MYCN status fewer than 5 copies, MLPA remains an effective molecular technique that enables a large panel of genomic aberrations screening. Thus combining CISH and MLPA is an effective molecular approach adopted in our laboratory. Our results allow pediatric oncologists to set up the first Neuroblastoma therapeutic strategy based on molecular markers in Tunisia.

Congenital heart disease in 37,294 births in Tunisia: birth prevalence and mortality rate.

AIM: To investigate the previously unknown birth incidence, treatment, and mortality of children with congenital heart disease in Tunisia. METHODS: We undertook a retrospective review of medical records of all patients who were born in 2010 and 2011, and were diagnosed in Sfax (Tunisia) with congenital heart defect. RESULTS: Among 37,294 births, 255 children were detected to have congenital heart disease, yielding a birth incidence of 6.8 per 1000. The most frequently occurring conditions were ventricular septal defects (31%), ostium secundum atrial septal defects (12.9%), and pulmonary valve abnormalities (12%). Coarctation of the aorta, tetralogy of Fallot, univentricular physiology, pulmonary atresia with ventricular septal defect, and transposition of the great arteries were found in 4.3%, 6.2%, 3.4%, 2.7%, and 2.7%, respectively. During the follow-up of 1 year, 23% of the children died. About three-quarters of those deaths happened before surgery. CONCLUSION: The present study is in line with the general estimates in the world. It has revealed a high case of mortality among the patients awaiting corrective surgery. These children need more facilities.

[Primary immune thrombocytopenia in childhood: a regional study in the south of Tunisia]. / Thrombocytopénie immune primaire de L'Enfant: etude régionale dans le sud Tunisien.

BACKGROUND: the primary immune thrombocytopenia (ITP) in children has a favorable evolution in most of cases. aim: describe the epidemiological and therapeutic data and the outcome of primary immune thrombocytopenia in our patients and propose a treatment plan to standardize the management of this disease in our region. methods: We conducted a retrospective study of 140 cases of primary immune thrombocytopenia collected in department of pediatrics and hematology of Hedi Chaker hospital during a period of 15 years. Patients who had a platelet count ≤ 20 000 and / or mucosal or troublesome lifestyle hemorrhage were treated. results: The mean age was 6 years 7 months with extremes varying from 3 months to 15 years. The bleeding manifestations were dominated by cutaneous bleeding in the form of petechiae or bruise (100%). Epistaxis and gingivorragia were noted in 32,9% and 25,7% of the cases respectively. The most of patient were treated with corticosteroids (79%). Intravenous immunoglobulin was associated with corticosteroids in 7%. An acute ITP occurred in 94 cases (67%) and a chronic ITP in 30 cases (21%). CONCLUSION: In the recently diagnosed ITP, the response delay under association Intravenous immunoglobulin and corticoids is shorter than that of corticoids alone, but the high cost of Intravenous immunoglobulin associated with their immediate side effects compels us to recommend corticoids as a first line of treatment.

[Aspirin and prevention of the recurrence of venous thromboembolism]. / Aspirine et prévention de la récidive de la maladie veineuse thromboembolique.

After a first episode of unprovoked vein thrombosis, the risk of recurrence persists for many years. Long term of anticoagulant therapy prevents the recurrence of vein thrombosis but is associated with a major risk of bleeding. As platelets play a role in the initiation and propagation of venous thromboembolism as well, antiplatelet agents, may play a role in the treatment and prevention of this disease. This review summarizes available evidence on effect of aspirin in the prevention of recurrent deep vein thrombosis.

Central retinal vein occlusion : an uncommon complication in sarcoidosis.

Sarcoidosis is a multi-system granulomatosis of unknown etiology, defined by the presence of epithelioid and gigantocellular granulomas, without caseous necrosis. Ocular sarcoidosis manifests mainly as bilateral granulomatous anterior uveitis. Occlusion of the central retinal vein in sarcoidosis is a rare manifestation, which is the particularity of our observation. We report the case of a patient presenting with unilateral central retinal vein occlusion associated with granulomatous anterior uveitis on the same side. Systemic manifestations and further investigations led to the diagnosis of sarcoidosis.

Clinical features and outcomes in patients with human immunodeficiency virus-negative, Castleman's disease: a single medical center study in Tunisia.

INTRODUCTION: Castleman's disease (CD), known as angiofollicular lymph node hyperplasia, is an uncommon condition. The two most common histological subtypes are hyaline vascular and plasma cell. We performed a retrospective analysis to define the clinic-pathological features and survival of CD, which is quite rare focusing on the particularities of our series with a review of the recent literature. METHODS: This is a retrospective study conducted in the department of internal medicine of Hedi Chaker hospital in Sfax, Tunisia over 25 years. The disease was histologically confirmed in all patients. For each file, we collected a set of data by filling in a pre-designed form. RESULTS: 18 patients were included. There were 8 men and 10 women with a mean age of 42.8 years. CD was monocentric in 5 cases (28%) and multicentric in 13 cases (72%). Clinically, peripheral adenopathy was present in 77.7% of patients and deep adenopathy in 72.2%. Systemic signs were found in 13 patients, including general condition (4.4%), fever (16.6%), serositis (27.7%), and skin involvement (33.3%). A biological inflammatory syndrome accompanied the clinical picture in 66% of patients. Abnormalities in the blood count were found in 12 cases (66%), with anemia in 11 cases, thrombocytosis in 3 cases, and hypereosinophilia in 3 cases. Cutaneous Kaposi's sarcoma was associated with Castleman's disease in 2 cases, Hodgkin's lymphoma, angioimmunoblastic T-cell lymphoma, and lymph node T-cell lymphoma were found in 1 case respectively. 3 of the patients had associated connective tissue diseases such as Sjögren's syndrome in 2 cases and rheumatoid arthritis in 1 case. HHV8 serology was positive in 1 case with a multicentric plasma cell form. Histologically, the plasma cell form represented 50% of cases, hyaline-vascular (39% of cases), and mixed (11% of cases). Therapeutically, high-dose corticosteroid therapy was initiated in 13 cases. As a second-line treatment, MOPP chemotherapy was used in 1 case due to transformation into Hodgkin's lymphoma, and biotherapy (rituximab) was used in 2 cases in the multicentric form. Surgical removal of superficial adenopathy was performed in 2 patients with monocentric CD. CONCLUSION: : Castleman's disease (CD) is a non-malignant lymphoproliferation of localized or multicentric form with a wide and heterogeneous clinical spectrum. Diagnosis can be difficult due to the lack of clinical and radiological specificity. Management depends on the clinical form involving surgical and/or medical management.

[Primary immunodeficiency disorders in 51 cases]. / Les déficits immunitaires primitifs de l'enfant. Etude de 51 observations.

BACKGROUND: Primary immunodeficiency disorders (PID) are a heterogeneous group of diseases, characterized by an increased susceptibility to infections. AIM: To determine the frequency of PID in south of Tunisia to collect information on clinical experience with these disorders. METHODS: Over a period of 16 years (1995 - 2010), primary immunodeficiency was confirmed in 51 patients (31 boys and 20 girls). The immunological investigation included a study of specific and/or non specific humoral and cellular immunity. RESULTS: These 51 patients belonged to 47 families among which 37 were consanguine (80%). The immunological investigations revealed a cellular or combined immunodeficiency in 21 cases, with a majority of ataxia-telangiectasia syndromes (11 cases), HLA class II deficiency (9 cases). A predominant antibody defect was found in 3 patients and a chronic granulomatous disease in seven cases. Deaths occurred So far in 19 patients (37 %). CONCLUSIONS: PID are relatively frequent in Tunisia, probably because of the high rate of consanguinity among the general population. The distribution of the different groups of primary immunodeficiencies is characterized by high frequency of ataxia - telangiectasia and HLA class II deficiency.

Febrile seizures: an epidemiological and outcome study of 482 cases.

INTRODUCTION: Febrile seizures (FSs) are the most common type of seizures seen in children. After the first FS, 3 to 12% of children develop epilepsy, and 30% of these patients present with recurrent FS. The purpose of this study was to describe the epidemiological aspects of FS in order to better define the long-term outcomes in children with first FS and to identify the risk factors associated with the recurrence of FS as well as the development of epilepsy. METHODS: A retrospective study of 482 children with FS was conducted from January of 2004 to December of 2009 in the pediatric department of Hedi Chaker University Hospital in Sfax, Tunisia. The medical records for each patient were first collected and then analyzed at a later time. RESULTS: The study included 482 children. Simple FSs were found in 55.2% of children, and complex FSs were observed in 44.8%. The mean duration for follow-up examinations was 2 years and 4 months, and ranged from 1 to 5 years. No deaths or permanent neurological deficits due to FSs were observed, and only six children (1%) developed epilepsy. A total of 57 children (11.7%) developed recurrent seizures. Our findings suggest that a family history of FS, young age at onset, and a low degree of fever were predictive of recurrent FSs. CONCLUSION: Children with FSs encounter a minor risk of mortality and morbidity. While recurrent seizures are observed in these children, only a minority of these patients develop epilepsy.

About a rare association: Guillain-Barré Syndrome and polymyositis.

Guillain-Barré syndrome (GBS) and polymyositis (PM) are two rare autoimmune diseases, one of which affects the peripheral nervous system and other the muscle. We report the case of a young woman with no previous medical history who was hospitalized with an ascending paralysis associated with acute respiratory failure due to a GBS. The patient was treated with plasmapheresis with unfavorable outcome and permanent proximal muscular disability. The diagnosis of an associated PM was retained based on biological myolysis and the results of electromyography and muscular biopsy. To our knowledge, this association of GBS and PM has been reported only once in the literature. The search for syndromic associations in the presence of an autoimmune helps to avoid diagnostic errors.

Custom Next-Generation Sequencing Identifies Novel Mutations Expanding the Molecular and clinical spectrum of isolated Hearing Impairment or along with defects of the retina, the thyroid, and the kidneys.

BACKGROUND: In the Tunisian population, the molecular analysis of hearing impairment remains based on conventional approaches, which makes the task laborious and enormously expensive. Exploration of the etiology of Hearing Impairment and the early diagnosis of causal mutations by next-generation sequencing help significantly alleviate social and economic problems. METHODS: We elaborated a custom SureSelectQXT panel for next-generation sequencing of the coding sequences of 42 genes involved in isolated hearing impairment or along with defects of the retina, the thyroid, and the kidneys. RESULTS: We report eight pathogenic variants, four of which are novel in patients with isolated hearing impairment, hearing impairment, and renal tubular acidosis, Usher syndrome and Pendred syndrome. Functional studies using molecular modeling showed the severe impact of the novel missense mutations on the concerned proteins. Basically, we identified mutations in nuclear as well as mitochondrial genes in a Tunisian family with isolated hearing impairment, which explains definitely the phenotype detected since 2006. CONCLUSION: Our results expanded the mutation spectrum and genotype-phenotype correlation of isolated and syndromic hearing loss and also emphasized the importance of combining both targeted next-generation sequencing and detailed clinical evaluation to elaborate a more accurate diagnosis for hearing impairment and related phenotypes especially in North African populations.

Molecular characterization of CTNS mutations in Tunisian patients with ocular cystinosis.

BACKGROUND: Ocular cystinosis is a rare autosomal recessive disorder characterized by intralysosomal cystine accumulation in renal, ophthalmic (cornea, conjunctiva), and other organ abnormalities. Patients with ocular cystinosis are mostly asymptomatic and typically experience mild photophobia due to cystine crystals in the cornea observed accidently during a routine ocular examination. The ocular cystinosis is associated with different mutations in CTNS gene. Cysteamine therapy mostly corrects the organ abnormalities. METHODS: This study was performed in collaboration with the department of ophthalmology of Farhat Hached Hospital. The Optical Coherence Tomography (OCT) of the cornea and retinal photography were used to search cystine crystals within the corneas and conjunctiva in eight Tunisian patients. Screening for the common 57-kb deletion was performed by standard multiplex PCR, followed by direct sequencing of the entire CTNS gene. RESULTS: The studied patients were found to have cystine crystal limited anterior corneal stroma and the conjunctiva associated with retinal crystals accumulation. CTNS gene sequencing disclosed 7 mutations: three missense mutations (G308R, p.Q88K, and p.S139Y); one duplication (C.829dup), one framshift mutation (p.G258f), one splice site mutation (c.681 + 7delC) and a large deletion (20,327-bp deletion). Crystallographic structure analysis suggests that the novel mutation p.S139Y is buried in a first transmembrane helix closed to the lipid bilayer polar region, introducing a difference in hydrophobicity which could affect the hydrophobic interactions with the membrane lipids. The second novel mutation p.Q88K which is located in the lysosomal lumen close to the lipid membrane polar head region, introduced a basic amino acid in a region which tolerate only uncharged residue. The third missense mutation introduces a positive change in nonpolar tail region of the phospholipid bilayer membrane affecting the folding and stability of the protein in the lipid bilayer. CONCLUSIONS: Our data demonstrate that impaired transport of cystine out of lysosomes is the most common, which is obviously associated with the mutations of transmembrane domains of cystinosine resulting from a total loss of its activity.

A novel m.3395A>G missense mutation in the mitochondrial ND1 gene associated with the new tRNA(Ile) m.4316A>G mutation in a patient with hypertrophic cardiomyopathy and profound hearing loss.

Mitochondria are essential for early cardiac development and impaired regulation of mitochondrial function was implicated in congenital heart diseases. We described a newborn girl with hypertrophic cardiomyopathy and profound hearing loss. The mtDNA mutational analysis revealed the presence of known polymorphisms associated to cardiomyopathy and/or hearing loss, and 2 novel heteroplasmic mutations: m.3395A>G (Y30C) occurring in a highly conserved aminoacid of the ND1 gene and the m.4316A>G located in the residue A54 of the tRNA(Ile) gene. These 2 novel variations were absent in 150 controls. All these variants may act synergistically and exert a cumulative negative effect on heart function to generate the cardiomyopathy.

A Tunisian patient with Pearson syndrome harboring the 4.977kb common deletion associated to two novel large-scale mitochondrial deletions.

Pearson syndrome (PS) is a multisystem disease including refractory anemia, vacuolization of marrow precursors and pancreatic fibrosis. The disease starts during infancy and affects various tissues and organs, and most affected children die before the age of 3years. Pearson syndrome is caused by de novo large-scale deletions or, more rarely, duplications in the mitochondrial genome. In the present report, we described a Pearson syndrome patient harboring multiple mitochondrial deletions which is, in our knowledge, the first case described and studied in Tunisia. In fact, we reported the common 4.977kb deletion and two novel heteroplasmic deletions (5.030 and 5.234kb) of the mtDNA. These deletions affect several protein-coding and tRNAs genes and could strongly lead to defects in mitochondrial polypeptides synthesis, and impair oxidative phosphorylation and energy metabolism in the respiratory chain in the studied patient.