Current phenotypic and genetic spectrum of syndromic deafness in Tunisia: paving the way for precision auditory health.

Hearing impairment (HI) is a prevalent neurosensory condition globally, impacting 5% of the population, with over 50% of congenital cases attributed to genetic etiologies. In Tunisia, HI underdiagnosis prevails, primarily due to limited access to comprehensive clinical tools, particularly for syndromic deafness (SD), characterized by clinical and genetic heterogeneity. This study aimed to uncover the SD spectrum through a 14-year investigation of a Tunisian cohort encompassing over 700 patients from four referral centers (2007-2021). Employing Sanger sequencing, Targeted Panel Gene Sequencing, and Whole Exome Sequencing, genetic analysis in 30 SD patients identified diagnoses such as Usher syndrome, Waardenburg syndrome, cranio-facial-hand-deafness syndrome, and H syndrome. This latter is a rare genodermatosis characterized by HI, hyperpigmentation, hypertrichosis, and systemic manifestations. A meta-analysis integrating our findings with existing data revealed that nearly 50% of Tunisian SD cases corresponded to rare inherited metabolic disorders. Distinguishing between non-syndromic and syndromic HI poses a challenge, where the age of onset and progression of features significantly impact accurate diagnoses. Despite advancements in local genetic characterization capabilities, certain ultra-rare forms of SD remain underdiagnosed. This research contributes critical insights to inform molecular diagnosis approaches for SD in Tunisia and the broader North-African region, thereby facilitating informed decision-making in clinical practice.

Cutaneous Metastases: Clinicopathologic Study of 30 Patients.

Cutaneous metastases (CMs) of internal malignancies are uncommon. The breast in women and the lung in men represent the two elective sites of internal malignancies metastasizing to the skin. The aim of this study was to determine the epidemiologic, clinical, and pathologic features of CMs. A retrospective study of the patients diagnosed with CMs over 30 years was conducted. Thirty cases of CMs were enrolled in our study. In 16 cases (53%), the skin metastasis revealed the internal malignancy. The mean age was 66.4 years with sex ratio men/women of 2. CMs were solitary in 18 cases and multiple in 14 cases. The most frequent location was the chest (12 cases), followed by the abdomen (eight cases), the scalp (seven cases), and the arms (six cases). The common sites of primary malignancy were the lungs in men (nine cases) and the breast in women (three cases). Nine out of 30 patients died with an average of 33 months after diagnosis. In our study, the most frequent primary malignancy in men was lung cancer and in women breast cancer. The onset of CMs during the course of internal malignancy worsens the prognosis of the disease.

Nail involvement in connective tissue diseases: an epidemiological, clinical, and dermoscopic study.

BACKGROUND: The assessment of nail changes in connective tissue diseases (CTD) has been rarely explored in previous studies. The use of dermoscopy to study vascular changes in nailfolds is an interesting diagnostic technique. The aim of the study was to describe the epidemiological, clinical, and dermoscopic features of nail lesions in CTD. METHODS: A prospective study was performed at the Dermatology Department of Habib Thameur Hospital (Tunis, Tunisia) in collaboration with the Internal Medicine Department over a period of 15 months, from July 2020 to September 2021, including patients diagnosed with systemic sclerosis (SS), systemic lupus erythematosus (SLE) and dermatomyositis (DM). RESULTS: Our study included 48 patients. Nail involvement was found in 44 cases. Dermoscopic nailfold abnormalities were identified in 37 cases. The most common clinical features were ragged cuticle, nailfold erythema, and onycholysis. Additionally, splinter hemorrhage, longitudinal ridging, lunula abnormalities, melanonychia, trachyonychia, leukonychia, increase in transverse curvature, parrot beak nail, half and half nails, and onychorrhexis were described. Nailfold dermoscopy showed a normal pattern in 10 cases, a nonspecific pattern in nine cases (SLE), and a scleroderma pattern in 29 cases (SS and DM). The scleroderma pattern was further categorized into an early pattern (6), an active pattern (14), and a late pattern (9). Normal pattern was observed solely in patients in remission. The late scleroderma pattern was associated with disease duration and systemic involvement. In SLE, disease activity correlated with onycholysis, nailfold erythema, and pathologic pattern in dermoscopy. However, patients with DM displayed a positive correlation between pulmonary involvement and scleroderma pattern. CONCLUSION: Nail involvement in CTD includes a diverse range of abnormalities. Despite being nonspecific, it can provide crucial clues for establishing a diagnosis. Nailfold dermoscopy serves as a mirror for microangiopathy, enabling the detection of changes at an initial stage, and thus, it becomes a diagnostic and prognostic tool.

Comorbidity of bathing suit ichthyosis and limb-girdle muscular dystrophy type 2 A in a Tunisian patient revealed by Whole Exome Sequencing.

Elevated rates of consanguinity and inbreeding are responsible for the high prevalence of recessively inherited diseases among inbred populations including Tunisia. In addition, the co-occurrence of two of these conditions, called also comorbidity, within the same individual or in members of the same family are often described in Tunisia which is challenging for diagnosis. The high throughput sequencing has improved the diagnosis of inherited diseases. We report here on a 32-year-old woman born to consanguineous parents. She presented with congenital ichthyosis and muscular dystrophy. She was primarily suspected as suffering from Chanarin-Dorfman syndrome (CDS) with unusual form. Screening of founder mutations allowed only the elucidation of the molecular etiology of Ichthyosis. As the result was inconclusive, Whole Exome Sequencing (WES) was conducted. WES data analysis led to the identification of a mutation in the CAPN3 gene underlying limb-girdle muscular dystrophy type 2A (LGMD2A). Sanger sequencing confirmed the familial segregation of mutations. This work presents the first case worldwide of individual comorbidity of bathing suit ichthyosis and LGMD2A. The co-occurrence of two diseases should be systematically considered when establishing a diagnosis especially in consanguineous populations. WES is a powerful tool for molecular diagnosis in particular for revealing comorbidities and rectifying the diagnosis.

Absent meibomian glands and cone dystrophy in ADULT syndrome: identification by whole exome sequencing of pathogenic variants in two causal genes TP63 and CNGB3.

BACKGROUND: Ectrodactyly is a rare congenital limb malformation characterized by a deep median cleft of the hand and/or foot due to the absence of central rays. It could be isolated or depicts a part of diverse syndromic forms. Heterozygous pathogenic variants in the TP63 gene are responsible for at least four rare syndromic human disorders associated with ectrodactyly. Among them, ADULT (Acro-Dermato-Ungual-Lacrimal-Tooth) syndrome is characterized by ectodermal dysplasia, excessive freckling, nail dysplasia, and lacrimal duct obstruction, in addition to ectrodactyly and/or syndactyly. Ophthalmic findings are very common in TP63-related disorders, consisting mainly of lacrimal duct hypoplasia. Absent meibomian glands have also been well documented in EEC3 (Ectrodactyly Ectodermal dysplasia Cleft lip/palate) syndrome but not in ADULT syndrome. METHODS: We report a case of syndromic ectrodactyly consistent with ADULT syndrome, with an additional ophthalmic manifestation of agenesis of meibomian glands. The proband, as well as her elder sister, presented with congenital cone dystrophy.The molecular investigation was performed in the proband using Whole Exome Sequencing. Family segregation of the identified variants was confirmed by Sanger sequencing. RESULTS: Two clinically relevant variants were found in the proband: the novel de novo heterozygous missense c.931A > G (p.Ser311Gly) in the TP63 gene classified as pathogenic, and the homozygous nonsense pathogenic c.1810C > T (p.Arg604Ter) in the CNGB3 gene. The same homozygous CNGB3 variation was also found in the sister, explaining the cone dystrophy in both cases. CONCLUSIONS: Whole Exome Sequencing allowed dual molecular diagnoses: de novo TP63-related syndromic ectrodactyly and familial CNGB3-related congenital cone dystrophy.

Idiopathic Granulomatous Mastitis Associated with Erythema Nodosum in a Pregnant Woman.

A 32-year-old woman at 17 weeks' gestation presented with fever and a 1-week history of an acute nodular eruption involving her legs, along with bilateral ankle and knee pain. She also had had a recurrent right breast abscess for 2 months for which she had been treated with oral antibiotics and surgical drainage, but with slight improvement. Cultures of the abscess showed no bacteria or fungi. She had no history of tuberculosis, sarcoidosis, trauma to the breast, or a family history of breast pathology. Cutaneous examination revealed multiple, tender, erythematous, subcutaneous nodules on her legs (Figure 1) and an ill-defined tender mass involving the inferior quadrant of the right breast without nipple discharge or retraction. There was a scar with drainage on her right breast (Figure 2). There were no regional lymphadenopathies. Left breast and left axilla examination was unremarkable. Significant laboratory findings included an erythrocyte sedimentation rate of 54 mm/hour (normal levels [NL] < 20 mm/hour), an elevated C reactive protein at 148 mg/L (NL < 5 mg/L), and a high level of white blood cells averaging 15,000 elements/mm3 (NL < 10,000/mm3).

Differential Expression of ATM, NF-KB, PINK1 and Foxo3a in Radiation-Induced Basal Cell Carcinoma.

Research in normal tissue radiobiology is in continuous progress to assess cellular response following ionizing radiation exposure especially linked to carcinogenesis risk. This was observed among patients with a history of radiotherapy of the scalp for ringworm who developed basal cell carcinoma (BCC). However, the involved mechanisms remain largely undefined. We performed a gene expression analysis of tumor biopsies and blood of radiation-induced BCC and sporadic patients using reverse transcription-quantitative PCR. Differences across groups were assessed by statistical analysis. Bioinformatic analyses were conducted using miRNet. We showed a significant overexpression of the FOXO3a, ATM, P65, TNF-α and PINK1 genes among radiation-induced BCCs compared to BCCs in sporadic patients. ATM expression level was correlated with FOXO3a. Based on receiver-operating characteristic curves, the differentially expressed genes could significantly discriminate between the two groups. Nevertheless, TNF-α and PINK1 blood expression showed no statistical differences between BCC groups. Bioinformatic analysis revealed that the candidate genes may represent putative targets for microRNAs in the skin. Our findings may yield clues as to the molecular mechanism involved in radiation-induced BCC, suggesting that deregulation of ATM-NF-kB signaling and PINK1 gene expression may contribute to BCC radiation carcinogenesis and that the analyzed genes could represent candidate radiation biomarkers associated with radiation-induced BCC.

Familial homozygous hypercholesterolemia with arcus cornea and xanthomas: A rare but serious entity.

Familial hypercholesterolemia (FH) is a rare but life-threatening disorder. Skin manifestations can be its only manifestation. We present a case of a fifteen-year-old female child, with multiple eruptive xanthomas, xanthomas anarcus, and a deranged lipid profile consistent with FH. The presence of this manifestation especially in the younger age group should draw attention to hypercholesterolemia. A timely diagnosis is fundamental to prevent serious complications and for early treatment.