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.

Man-O-War simulator: a Low-cost manikin for training on chest tube management.

Simulation-based medical education is becoming a cornerstone in health education. Simulators are commonly expensive and not available in developing countries. We propose a very low-cost simulator that any educator can realize. We describe here the steps to follow to develop this proposed simulator.

A novel WFS1 variant associated with severe diabetic retinopathy in Wolfram syndrome type 1.

BACKGROUND: Wolfram syndrome type 1 is a rare neurodegenerative disorder including diabetes insipidus, diabetes mellitus, optic atrophy, and deafness, with variable additional findings. The phenotypic spectrum is very heterogeneous, with non-autoimmune juvenile-onset diabetes and optic atrophy as minimal criteria for the diagnosis. Biallelic mutations in the WFS1 gene are the causative genetic anomaly for the syndrome, with, however, no evident genotype-phenotype correlation. Among the clinical features of the disease, diabetic retinopathy depicts a rarely reported microvascular complication. In this report, we describe the clinical and genetic findings in a 26-year-old patient presenting with Wolfram syndrome and severe diabetic retinopathy. METHODS: The mutation screening was performed by polymerase chain reaction followed by Sanger sequencing of the entire coding sequence of the WFS1 gene. RESULTS: A novel homozygous missense variant c.1901A>T (p.Lys634Met) was found in the proband and classified as probably pathogenic according to the American College of Medical Genetics and Genomics. CONCLUSIONS: The molecular study of the WFS1 gene is essential for the diagnostic confirmation, to provide appropriate genetic counseling and a mutational screening in the at-risk relatives. The c.1901A>T (p.Lys634 Met) is a novel variant that could be responsible for a severe form of Wolfram syndrome with early and proliferative diabetic retinopathy.

Craniofacial Malformations as Fundamental Diagnostic Tools in Syndromic Entities.

Background: A long list of syndromic entities can be diagnosed immediately through scrutinizing the clinical phenotype of the craniofacial features. The latter should be assisted via proper radiological interpretations. Patients and Methods: Different children aged from 1 month to 12 years were referred to our departments seeking orthopedic advice. Primarily, all received variable false diagnoses in other institutes. Two unrelated boys of one month and 12 months were falsely diagnosed as having positional plagiocephaly associated with contractures of idiopathic origin. Two unrelated boys of 14 months and 2 years were diagnosed with pseudo-hydrocephalus and non-specific syndrome, and were referred to explore their skeletal development. Two unrelated girls of 4 years old and 12 years old presented with multiple contractures were referred because of progressive scoliosis. A 4-year-old girl was referred with a false provisional diagnosis of facial diplegia. All children underwent detailed clinical, radiological and tomographic phenotypic characterizations and genetic testing, respectively. Results: Idaho syndrome (craniosynostosis associated with multiple dislocations) was the final diagnosis in the two unrelated boys with plagiocephaly and multiple contractures. Two children falsely diagnosed with pseudo-hydrocephalus and non-specific syndrome, were diagnosed with Silver-Russell syndrome (RSS). Contractural arachnodactyly Beals (CAB) was confirmed as the definitive diagnosis in the two unrelated girls with progressive scoliosis and multiple contractures. Parry-Romberg syndrome (PRS) associated with congenital lumbar kyphosis was the final diagnosis of the girl with the diagnosis of facial diplegia. Hypomethylation of ICR1 was confirmed in the RSS patients. Whole exome sequencing (WES) revealed a heterozygous mutation in the PRS patients. WES and array-CGH showed that no relevant variants or copy number variations (CNV) were identified in the CAB patients. Conclusions: On the one hand, newborn children can manifest diverse forms of abnormal craniofacial features, which are usually associated with either major or minor dysmorphic stigmata. A cleft lip/ palate is a major craniofacial malformation, and frontal bossing or a disproportionate craniofacial contour can be falsely considered as a transient plagiocephaly, which is spontaneously resolved by time. On the other hand, many physicians fall into the problem of deeming a countless number of diseases, such as contractures, as an idiopathic or non-specific syndrome. The latter stems from limited clinical experience. Therefore, failing to establish between the onset of the deformity and other inexplicit abnormal features that the patient or their immediate families or relatives carry is the final outcome. In this study, we used, for the first time, a reconstruction CT scan to further delineate the congenital disruption of the craniofacial anatomy and the other skeletal malformation complex.

A rare homozygous p.Arg87Trp variant of the GBA gene in Gaucher disease: A case report.

Gaucher disease (GD) is a rare metabolic disorder due to pathogenic variants in the GBA gene. We report the first case of the rare p.Arg87Trp pathogenic variant (formerly known as R48W) of the GBA gene in the Tunisian population. A female Arab patient was assessed at the age of 26 due to abdominal distension, bone pain, and headache since she was 25. Physical examination revealed splenomegaly, rib deformation, lumbar scoliosis, and upper limb tremor. Bone marrow was infiltrated by Gaucher cells. The patient was homozygous for the rare p.Arg87Trp variant which is known to be associated with a mild phenotype. This report highlights the necessity of screening the Tunisian population for this rare variant.

Beckwith-Wiedemann syndrome: Clinical, histopathological and molecular study of two Tunisian patients and review of literature.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is a rare overgrowth syndrome characterized by congenital malformations and predisposition to embryonic tumors. Loss of methylation of imprinting center 2 (IC2) is the most frequent alteration and rarely associated with tumors compared to paternal uniparental disomy of chromosome 11 (UPD(11)pat) and gain of methylation of imprinting center 1. METHODS: Our study aimed to describe the clinical, histopathological and genetic characteristics of two patients and establish genotype-phenotype correlations. The clinical diagnosis was based on the criteria defined by the international expert consensus of BWS. Molecular study of 11p15.5 methylation status was assessed using methylation-specific-multiplex ligation probe amplification (MS-MLPA). RESULTS: Patients were aged 12 months and 3 months and fulfilled the clinical score of BWS. MS-MLPA showed molecular alterations consisting of loss of methylation in IC2 (IC2-LOM) at the maternal allele for one patient and a mosaic UPD(11)pat for the second patient in whom follow-up at 6months revealed adrenocortical carcinoma (ACC) with low grade of malignancy. Molecular subtypes guide the follow-up and tumor surveillance, our major concern. CONCLUSION: We have to take into account the psychological impact of a possible tumor whatever the underlying mechanism is. Nevertheless, the tumor risk remains high for UPD(11)pat. Our study extended the phenotype of BWS with absence of macrosomia in Tunisian patients, contrasting with literature, and added a supplementary case of ACC in the tumor spectrum of BWS patients with UPD(11)pat.

New familial cases of karyomegalic interstitial nephritis with mutations in the FAN1 gene.

BACKGROUND: Karyomegalic interstitial nephritis (KIN) is a rare disease entity first described by Burry in 1974. The term KIN was introduced by Mihatsch et al. in 1979. KIN is characterized by chronic tubulointerstitial nephritis associated with enlarged tubular epithelial cell nuclei, which leads to a progressive decline of renal function. The prevalence of this disease is less than 1% of all biopsies, and its pathogenesis is unclear. KIN results from mutations in FAN1 (FANCD2/FANCI-Associated Nuclease 1), a gene involved in the DNA damage response pathway, particularly in the kidney. In this study, we report two Tunisian consanguineous families with KIN caused by mutations in the FAN1 gene. METHODS: Direct sequencing of the coding regions and flanking intronic sequences of the FAN1 gene was performed in three affected members. Three prediction programs (Polyphen-2 software, SIFT, and MutationTaster) were used to predict the functional effect of the detected variations. RESULTS: Two causative frameshift variants in the FAN1 gene were identified in each family: The previously described frameshift mutation c.2616delA (p.Asp873ThrfsTer17) and a novel mutation c.2603delT (p.Leu868ArgfsTer22) classified as "pathogenic" according to the American College of Medical Genetics and Genomics (ACMG) guidelines. CONCLUSION: To our best knowledge, this is the first Tunisian study involving familial cases of KIN with mutations in the FAN1 gene. We hypothesize that these findings can expand the mutational spectrum of KIN and provide valuable information on the genetic cause of KIN.

Stroke knowledge among emergency centre visitors: A cross-sectional multicenter survey.

INTRODUCTION: Stroke is a public health problem worldwide. Community stroke knowledge is crucial to guide the prevention approach. We aimed to evaluate the level of stroke knowledge among the visitors to Emergency Centres (ECs) in the southern region of Tunisia concerning factors of risk, symptoms, and treatment of stroke. METHODS: A multicenter cross-sectional survey about stroke knowledge; conducted in five ECs for 10 days. All the visitors to these ECs were invited to participate in this survey. In each center, one investigator had to conduct the questionnaire. We used the stroke knowledge test (SKT). RESULTS: We enrolled 839 participants aged at 44 ± 7 years and with an M/F sex-ratio at 0.9. Relatives and mass media were the most reported sources of information about stroke. In 32.3% of cases, the participants had a university schooling level. The upper quartile had an SKT score of 55% or over (n = 247; 29.4%). The SKT score was significantly higher in young, female participants, in rural centers, with a university level of schooling and with no reported chronic diseases. Receiving information about stroke through the medium of television or via relatives was an independent predictor of a high SKT score compared with other knowledge sources. CONCLUSION: This study emphasises the urgent need for improving the population's knowledge about stroke in Tunisia. These findings may reflect the lack of government policies for education and training on stroke. A national educating program is necessary to implement to increase stroke knowledge.

Mucopolysaccharidosis type VII as a cause of recurrent Non-Immune Hydrops Fetalis: The first Tunisian case confirmed by Next-Generation Sequencing.

Non-Immune Hydrops Fetalis (NIHF) is an intrauterine condition characterized by excessive fluid accumulation in at least two fetal compartments in the absence of maternal circulating red cell antibodies. It is associated with a poor prognosis and a wide etiological spectrum. Among the metabolic causes, Mucopolysaccharidosis type VII depicts the most frequent type of lysosomal storage disorders in the cause of NIHF. Nonetheless, it remains an ultra-rare disorder, as less than 150 cases have been reported in the literature. This rarity seems to be related to misdiagnosis since the underlying etiology remains unelusive in most cases of NIHF. In this report, we describe the first Tunisian case of Mucopolysaccharidosis type VII caused by a homozygous mutation in the GUSB gene confirmed by a Next-Generation Sequencing gene panel in a patient with recurrent NIHF.

First case report of Cohen syndrome in the Tunisian population caused by VPS13B mutations.

BACKGROUND: Cohen syndrome is a rare autosomal recessive developmental disorder that comprises variable clinical features counting developmental delay, pigmentary retinopathy, myopia, acquired microcephaly, truncal obesity, joint hypermobility, friendly disposition and intermittent neutropenia. VPS13B (vacuolar protein sorting 13, yeast, homologue of B) gene is the only gene responsible for Cohen Syndrome, causative mutations include nonsense, missense, indel and splice-site variants. The integrity of the Golgi apparatus requires the presence of the peripheral membrane protein VPS13B that have an essential function in intracellular protein transport and vesicle-mediated sorting. CASE PRESENTATION: In this study, we performed whole exome sequencing (WES) in a Tunisian family with two young cases having developmental delay, hypotonia, autism spectrum disorder, ptosis and thick hair and eyebrows. The proposita presented also pigmentory retinopathy. Compound heterozygous mutation in VPS13B gene was detected by WES. This mutation inherited from healthy heterozygous parents, supports an unpredictable clinical diagnosis of Cohen Syndrome. The proband's phenotype is explained by the presence of compound heterozygous mutations in the VPS13B gene. This finding refined the understanding of genotype-phenotype correlation. CONCLUSIONS: This is the first report of a Tunisian family with Cohen syndrome mutated in the VPS13B gene.

Epidemiological features of stress hyperglycemia in elderly at emergency department.

UNLABELLED: Background : Stress hyperglycemia among patients having an acute pathology is frequently described in recent studies. AIMS: The objectives of this work were to describe epidemiologic features of elderly patients hospitalized in the emergency department and having a hyperglycemia due to stress. METHODS: A retrospective chart review identified patients older than 65 years with obtained serum glucose levels. Patients with diabetes were excluded. Two levels of serum glucose were considered (>6,9 mmol/l and ≤ 6,9 mmol/l).   RESULTS: We included 165.  There were 94 patients with high level of serum glucose level (56,9%). Multivariate analysis found that only cardio-vascular pathologies were more predictive of having stress hyperglycemia (p=0,014, odds-ratio=2,8, IC=1,2-6,4). There were no correlation between serum glucose levels and mortality. CONCLUSION: Stress hyperglycemia is a fairly common disorder but underestimated in emergency department. Its impact on the prognosis of elderly patients remains to be studied.

Arg924X homozygous mutation in insulin receptor gene in a Tunisian patient with Donohue syndrome.

Donohue syndrome (DS) is a rare and lethal autosomal recessive disease caused by mutations in the insulin receptor (INSR) gene, manifesting marked insulin resistance, severe growth retardation, hypertrichosis, and characteristic dysmorphic features. We describe a new case of Donohue syndrome born at 37 weeks' gestation of unrelated parents and presented with intra-uterine growth retardation, nipple hypertrophy, macropenis, distended abdomen, hirsutism and dysmorphic features. The clinical course showed failure to thrive, and episodes of alternating hypoglycemia and hyperglycemia. Laboratory tests revealed direct hyperbilirubinemia. The diagnosis of Donohue syndrome was established based on the above clinical characteristics and determination of the INSR mutation. He was found to have homozygous nonsense mutation c. 2270 C>T (Arg924X) at exon 14 of the INSR gene. He later developed enterocolitis and died at 3 months old. Prenatal diagnosis was performed for the family via chorionic villous biopsy. We try to explain gastrointestinal dysfunction seen in our patient.

Mosaic parental germline mutations causing recurrent forms of malformations of cortical development.

To unravel missing genetic causes underlying monogenic disorders with recurrence in sibling, we explored the hypothesis of parental germline mosaic mutations in familial forms of malformation of cortical development (MCD). Interestingly, four families with parental germline variants, out of 18, were identified by whole-exome sequencing (WES), including a variant in a new candidate gene, syntaxin 7. In view of this high frequency, revision of diagnostic strategies and reoccurrence risk should be considered not only for the recurrent forms, but also for the sporadic cases of MCD.

Prediction value of the Canadian CT head rule and the New Orleans criteria for positive head CT scan and acute neurosurgical procedures in minor head trauma: a multicenter external validation study.

STUDY OBJECTIVE: The New Orleans Criteria and the Canadian CT Head Rule have been developed to decrease the number of normal computed tomography (CT) results in mild head injury. We compare the performance of both decision rules for identifying patients with intracranial traumatic lesions and those who require an urgent neurosurgical intervention after mild head injury. METHODS: This was an observational cohort study performed between 2008 and 2011 on patients with mild head injury who were aged 10 years or older. We collected prospectively clinical head CT scan findings and outcome. Primary outcome was need for neurosurgical intervention, defined as either death or craniotomy, or the need of intubation within 15 days of the traumatic event. Secondary outcome was the presence of traumatic lesions on head CT scan. New Orleans Criteria and Canadian CT Head Rule decision rules were compared by using sensitivity specifications and positive and negative predictive value. RESULTS: We enrolled 1,582 patients. Neurosurgical intervention was performed in 34 patients (2.1%) and positive CT findings were demonstrated in 218 patients (13.8%). Sensitivity and specificity for need for neurosurgical intervention were 100% (95% confidence interval [CI] 90% to 100%) and 60% (95% CI 44% to 76%) for the Canadian CT Head Rule and 82% (95% CI 69% to 95%) and 26% (95% CI 24% to 28%) for the New Orleans Criteria. Negative predictive values for the above-mentioned clinical decision rules were 100% and 99% and positive values were 5% and 2%, respectively, for the Canadian CT Head Rule and New Orleans Criteria. Sensitivity and specificity for clinical significant head CT findings were 95% (95% CI 92% to 98%) and 65% (95% CI 62% to 68%) for the Canadian CT Head Rule and 86% (95% CI 81% to 91%) and 28% (95% CI 26% to 30%) for the New Orleans Criteria. A similar trend of results was found in the subgroup of patients with a Glasgow Coma Scale score of 15. CONCLUSION: For patients with mild head injury, the Canadian CT Head Rule had higher sensitivity than the New Orleans Criteria, with higher negative predictive value. The question of whether the use of the Canadian CT Head Rule would have a greater influence on head CT scan reduction requires confirmation in real clinical practice.

The first missense mutation of NHS gene in a Tunisian family with clinical features of NHS syndrome including cardiac anomaly.

Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome is a disease of unknown gene action mechanism, characterized by congenital cataract, dental anomalies, dysmorphic features and, in some cases, mental retardation. We performed linkage analysis in a Tunisian family with NHS in which affected males and obligate carrier female share a common haplotype in the Xp22.32-p11.21 region that contains the NHS gene. Direct sequencing of NHS coding exons and flanking intronic sequences allowed us to identify the first missense mutation (P551S) and a reported SNP-polymorphism (L1319F) in exon 6, a reported UTR-SNP (c.7422 C>T) and a novel one (c.8239 T>A) in exon 8. Both variations P551S and c.8239 T>A segregate with NHS phenotype in this family. Although truncations, frame-shift and copy number variants have been reported in this gene, no missense mutations have been found to segregate previously. This is the first report of a missense NHS mutation causing NHS phenotype (including cardiac defects). We hypothesize also that the non-reported UTR-SNP of the exon 8 (3'-UTR) is specific to the Tunisian population.

A novel frame shift mutation in the PQBP1 gene identified in a Tunisian family with X-linked mental retardation.

Mental retardation (MR) is the most frequent cause of serious handicap in children and young adults. Despite recent progress, in most cases the molecular defects underlying this disorder remain unknown. Linkage studies followed by mutational analysis of known X-chromosomal genes related to mental retardation (MRX genes) localized within defined genetic intervals represent a rational strategy to identify a genetic cause of the disorder. Here, we report a Tunisian family including 3 males with severe to mild mental retardation, short stature, lean body and microcephaly; we mapped the disease to a unique interval encompassing Xp21.1-Xq21.33 (with a maximum LOD score of 0.90). Subsequent mutation analysis of genes located in this interval allowed us to identify a truncating mutation in the PQBP1 gene. This mutation is an insertion of an adenosine residue in exon 5 (c.631insA). This frameshift insertion causes premature stop codon at amino acid position 226. The observed mutation was found in all males with MR in this family. Together with previously reported observations, our data further confirm that PQBP1 gene should be tested for males showing mental retardation, short stature, lean body and microcephaly.

Subtelomeric microduplications in three sisters with moderate mental retardation.

Copy number changes of subtelomeric regions are a common cause of mental retardation, occurring in approximately 5% of mentally retarded patients. New molecular techniques allow the identification of subtelomeric microduplications. We report a Tunisian family of three sisters with moderate mental retardation, facial dysmorphism, cardiopathy, and bilateral clinodactyly of the third and fourth toes, explored by MLPA, showing the same associated microduplications, 15q and Xq, without a concurrent deletion.

X linked mental retardation.

BACKGROUND: Mental retardation (MR) is a group of heterogeneous clinical conditions. There are more than 900 genetic disorders associated with MR and it affects around 3% of the general population. Many MR conditions described are syndromic, fragile X syndrome being the most common clinical entity among them. X linked mental retardation (XLMR) is subdivided in two categories: syndromic XLMR (MRXS) when MR is associated with clinical features and non-syndromic XLMR (MRX) when MR is isolated. AIM: The aim of this systematic review of the literature was to join together the results of several studies related to X linked mental retardation and to present various genes implicated in this disease. In this review, focus has been given on genes implicated in mental retardation, the clinical data and on phenotype-genotype correlations. METHODS: An exhaustive electronic and library research of the recent literature was carried out on the Web sites "Science Direct" and "Interscience Wiley". The key words used were "mental retardation", "X chromosome", "gene", "syndromic mental retardation", "non-syndromic mental retardation". RESULTS: In this review a number of X linked genes, the clinical features associated with the gene abnormality, and the prevalence of the disease gene are discussed. We classified these genes by order of their first implication in MR. A table presented on the XLMR Update Web site who list the 82 known XLMR genes is available as XLMR Genes and corresponding proteins.

A novel splice mutation in PAK3 gene underlying mental retardation with neuropsychiatric features.

PAK3-related mental retardation represents a rare cause of X-linked mental retardation associated with behavioural symptoms. So far, four families carrying PAK3 mutations have been reported, and in most cases PAK3 dysfunction resulted from missense mutations thought to affect either the catalytic or the N-terminal regulatory domain activity. Here, we report on a Tunisian family of X-linked moderate mental retardation with behavioural symptoms, common dysmorphic features, oro-motor impairment and secondary microcephaly. Linkage analysis showed that affected male subjects and obligate carrier female subjects share a common haplotype in the Xp21.31 - Xq23 region that contains the PAK3 gene. Direct sequencing of PAK3 coding exons and flanking intronic sequences allowed us to identify the first splice mutation in PAK3 gene located at the 5' end of intron 6 (c.276+4A>G), which results in a complete switch-off of the genuine donor splice site and an activation of a cryptic donor splice site (GTAAG) located four nucleotides downstream to the genuine one. RT-PCR experiments using the RNA from the patient's lymphoblasts showed that PAK3 transcripts contain four additional nucleotides that lead to a disruption of reading frame with a premature stop codon at position 128. Together with previously reported observations, our data further confirm that PAK3 mutations result in a specific form of X-linked mental retardation with fairly constant clinical features.