Clonal Hematopoiesis and Risk of Atherosclerotic Cardiovascular Disease.

BACKGROUND: Clonal hematopoiesis of indeterminate potential (CHIP), which is defined as the presence of an expanded somatic blood-cell clone in persons without other hematologic abnormalities, is common among older persons and is associated with an increased risk of hematologic cancer. We previously found preliminary evidence for an association between CHIP and atherosclerotic cardiovascular disease, but the nature of this association was unclear. METHODS: We used whole-exome sequencing to detect the presence of CHIP in peripheral-blood cells and associated such presence with coronary heart disease using samples from four case-control studies that together enrolled 4726 participants with coronary heart disease and 3529 controls. To assess causality, we perturbed the function of Tet2, the second most commonly mutated gene linked to clonal hematopoiesis, in the hematopoietic cells of atherosclerosis-prone mice. RESULTS: In nested case-control analyses from two prospective cohorts, carriers of CHIP had a risk of coronary heart disease that was 1.9 times as great as in noncarriers (95% confidence interval [CI], 1.4 to 2.7). In two retrospective case-control cohorts for the evaluation of early-onset myocardial infarction, participants with CHIP had a risk of myocardial infarction that was 4.0 times as great as in noncarriers (95% CI, 2.4 to 6.7). Mutations in DNMT3A, TET2, ASXL1, and JAK2 were each individually associated with coronary heart disease. CHIP carriers with these mutations also had increased coronary-artery calcification, a marker of coronary atherosclerosis burden. Hypercholesterolemia-prone mice that were engrafted with bone marrow obtained from homozygous or heterozygous Tet2 knockout mice had larger atherosclerotic lesions in the aortic root and aorta than did mice that had received control bone marrow. Analyses of macrophages from Tet2 knockout mice showed elevated expression of several chemokine and cytokine genes that contribute to atherosclerosis. CONCLUSIONS: The presence of CHIP in peripheral-blood cells was associated with nearly a doubling in the risk of coronary heart disease in humans and with accelerated atherosclerosis in mice. (Funded by the National Institutes of Health and others.).

Physical activity, smoking, and genetic predisposition to obesity in people from Pakistan: the PROMIS study.

BACKGROUND: Multiple genetic variants have been reliably associated with obesity-related traits in Europeans, but little is known about their associations and interactions with lifestyle factors in South Asians. METHODS: In 16,157 Pakistani adults (8232 controls; 7925 diagnosed with myocardial infarction [MI]) enrolled in the PROMIS Study, we tested whether: a) BMI-associated loci, individually or in aggregate (as a genetic risk score--GRS), are associated with BMI; b) physical activity and smoking modify the association of these loci with BMI. Analyses were adjusted for age, age(2), sex, MI (yes/no), and population substructure. RESULTS: Of 95 SNPs studied here, 73 showed directionally consistent effects on BMI as reported in Europeans. Each additional BMI-raising allele of the GRS was associated with 0.04 (SE = 0.01) kg/m(2) higher BMI (P = 4.5 × 10(-14)). We observed nominal evidence of interactions of CLIP1 rs11583200 (P(interaction) = 0.014), CADM2 rs13078960 (P(interaction) = 0.037) and GALNT10 rs7715256 (P(interaction) = 0.048) with physical activity, and PTBP2 rs11165643 (P(interaction) = 0.045), HIP1 rs1167827 (P(interaction) = 0.015), C6orf106 rs205262 (P(interaction) = 0.032) and GRID1 rs7899106 (P(interaction) = 0.043) with smoking on BMI. CONCLUSIONS: Most BMI-associated loci have directionally consistent effects on BMI in Pakistanis and Europeans. There were suggestive interactions of established BMI-related SNPs with smoking or physical activity.

Cross-sectional study identifying forms of tobacco used by Shisha smokers in Pakistan.

OBJECTIVES: To estimate the frequency of different forms of tobacco intake such as smoker's tobacco, chewable tobacco and snuff tobacco among shisha smoker's and to study the patterns and predictors of shisha smoking affecting youth from different cities of Pakistan. METHODS: A cross-sectional study was conducted including youth from four cities. Participants were asked to fill out a data collection tool at shisha cafes, shopping malls and restaurants. Data was analyzed using SPSSv.18. RESULTS: A total of 406 participants, 296 (73%) males and 110 (27%) females were included in the study. There were 163 (40%) cigarette smokers; 65 (16%) chewed tobacco and 33 (8%) snuffed it. The median age at initiation of Shisha smoking was 20 years. 280 (69%) considered Shisha smoking to be less deleterious to health than cigarettes. Respiratory disease was the most commonly cited health effect reported. Most 248 (61%) of the participants were infrequent shisha smokers. CONCLUSION: There is high frequency of tobacco usage in the form of cigarettes, chewable tobacco and snuff tobacco among shisha smokers of Pakistan. The highest frequency is for cigarette smoking. The rise in Shisha smoking as a trendy social habit appears to be occurring despite emerging scientific evidence of its potential health risks.

Evaluation of therapeutic control in a Pakistani population with hypertension.

RATIONALE, AIMS AND OBJECTIVES: Cardiovascular diseases (CVD) are increasing at an alarming rate in South Asia. High blood pressure is a modifiable risk factor for CVD. In this study, we evaluated the control of blood pressure and the prevalence of cardiovascular risk factors in patients with hypertension. METHOD: A cross-sectional study was conducted in 50 primary health care centres throughout Pakistan. Individuals with a documented history of hypertension, receiving pharmacological therapy, were enrolled and evaluated for the control of their blood pressure. RESULTS: The recommended therapeutic control of hypertension (systolic blood pressure <140 mmHg, diastolic blood pressure <90 mmHg) was seen in only 6.4% of the study participants. Values of both the mean systolic and diastolic blood pressures in all subjects were higher than the desired therapeutic levels (P<0.001). There was a high prevalence in the study population of established but modifiable risk factors of CVD, such as smoking (30.5%), hypercholesterolemia (59.5%) and sedentary lifestyle (43.5%). Lack of therapeutic control of systolic blood pressure was found significantly associated with age, hypercholesterolemia and sedentary lifestyle (P<0.05). CONCLUSIONS: Patients being treated at primary health care centres in Pakistan have inadequate control of high blood pressure. Evidence-based continuous education of primary health care physicians is a necessary intervention for optimizing treatment strategies and achieving better therapeutic control of hypertension in our population.

The cradle of the deltaF508 mutation.

Cystic fibrosis (CF) is the most common autosomal recessive disorder caused due to mutation/s in the CFTR gene. The most common mutation in CFTR worldwide is deltaF508 and cystic fibrosis genetic analysis consortium revealed that this mutation is responsible for approximately 66% of all CF chromosomes in the world. Studies looking at the DNA polymorphic haplotypes created by CF linked markers suggest that deltaF508 has a single origin as this mutation has been found associated exclusively with one marker haplotype. Despite a high prevalence of this mutation in CF patients in northern parts of Europe, findings suggest that this mutation was not spread by Europeans but by a group that is speculated to have originated in the Middle East or a more eastern region in Asia (most likely subcontinent). Over here we have given a brief introduction to cystic fibrosis and classification of CFTR mutations and have further elaborated on the crucial issue about the spread of the deltaF508 mutation. We have reviewed findings that give clues about the origin of this mutation from the Baluch ethnicity residing in Pakistan.

Novel mutation in the PANK2 gene leads to pantothenate kinase-associated neurodegeneration in a Pakistani family.

Pantothenate kinase-associated neurodegeneration is an autosomal-recessive disorder associated with the accumulation of iron in the basal ganglia. The disease presents with dystonia, rigidity, and gait impairment, leading to restriction of activities and loss of ambulation. The disorder is caused by defective iron metabolism associated with mutations in the PANK2 gene, which codes for the pantothenate kinase enzyme. We report on a mutation screen conducted in two siblings to establish a molecular diagnosis of the disease and a genetic test for the family.

3120+1 G-->A: a rare variant in Emirati CF patients.

Cystic fibrosis is a multi-system genetic disorder caused by mutation in the cystic fibrosis conductance transmembrane regulator (CFTR) gene located on chromosome 7. In United Arab Emirates (UAE), pattern of CF causing gene mutations is different than rest of the Arabs in the region and 95% of CF in Emirati families has been found due to two mutations only - -p.S549R(T>G) and p.F508del. We report the case of a homozygote for a mutation 3120 +1G-->A in the Emirati population detected in a young boy referred to CF and Respiratory Clinic at Tawam Hospital (Al Ain, UAE) for screening CFTR gene.

[3120+1kbdel8.6kb]+[p.N1303K] genotype in an Emirati cystic fibrosis patient: indication of a founder mutation in Palestinian Arabs.

Cystic fibrosis (CF) is the most common life-limiting autosomal recessive disorder in Caucasian population. The disease was initially considered to be rare in Middle Eastern countries. 95% of CF in Emirati families is due to two mutations only--p.S549R(T > G) and p.F508del. We report here the case of a patient referred to CF and Respiratory Clinic at Tawam Hospital for cystic fibrosis transmembrane regulator (CFTR) gene screening to ascertain the diagnosis of CF, who was found to carry a unique genotype, signifying the importance of retrieving ancestral histories of patients with monogenic disorders.

Association of ACE polymorphisms with left ventricular hypertrophy.

The angiotensin converting enzyme gene (ACE) is a candidate gene for an individual's genetic susceptibility to left ventricular hypertrophy (LVH). LVH has long been thought to be an end point of essential hypertension (EH), rather than a separate entity, though it is influenced by a unique set of hormonal, vascular and genetic factors. In this study, we attempted to determine whether two representative polymorphisms of the ACE gene, ACE I/D and 2350 G>A, known to be associated with EH and to influence plasma ACE levels most significantly, could implicate ACE as a quantitative trait locus (QTL) for LVH. We carried out a retrospective, case-control study of the two ACE polymorphisms amongst 180 nationals (50 LVH patients and 130 controls) from the United Arab Emirates--an ethnic group characterized by no alcohol intake and no cigarette smoking--for correlations with LVH. Clinical diagnosis of LVH was based on echocardiographic and ECG criteria. ACE I/D and 2350 G>A genotypes were determined by PCR and restriction digestion. Univariate and multivariate logistic regression analyses revealed an association between ACE polymorphisms and LVH. Haplotype analysis further supported this finding. ACE I/D and ACE 2350 G>A polymorphisms are in strong linkage disequilibrium and are associated with LVH, suggesting that ACE is likely to be a QTL for LVH.

Association of angiotensin converting enzyme gene polymorphisms with left ventricular hypertrophy.

The angiotensin converting enzyme gene (ACE) is of much interest as a candidate gene conferring an individual's genetic susceptibility to left ventricular hypertrophy (LVH). LVH has long been thought to be an end point of essential hypertension (EH), rather than a separate entity, though it is influenced by a unique set of hormonal, vascular and genetic factors. In this study, we attempted to determine whether two representative polymorphisms of the ACE gene, ACE I/D and 2350 G>A, known to be associated with EH and to have a highly significant influence on plasma ACE levels, could implicate ACE as a quantitative trait locus (QTL) for LVH. We carried out a retrospective, case-control study of the two ACE polymorphisms amongst 180 nationals (50 LVH patients and 130 controls) from the United Arab Emirates (Emirati)--an ethnic group characterized by an absence of alcohol intake and cigarette smoking--for putative correlations with LVH. Clinical diagnoses of LVH were based on echocardiographic and ECG criteria. ACE I/D and 2350 G>A genotypes were determined by polymerase chain reaction (PCR) and restriction digestion. Univariate and multivariate logistic regression analyses revealed an association between ACE polymorphisms and LVH. Haplotype analysis further supported this finding. The ACE I/D and ACE 2350 G>A polymorphisms were in strong linkage disequilibrium and were independently associated with LVH, suggesting that ACE is likely to be a QTL for LVH. In conclusion, This is the first association study of the ACE 2350 G>A polymorphism with LVH; the results showed that this polymorphism, along with ACE I/D, is associated with LVH.

Association of G-protein beta-3 subunit gene (GNB3) T825 allele with Type II diabetes.

To date, the human G-protein beta 3 subunit (GNB3) gene and some of its variants represent some of the best examples of genetic influences that are involved in the determination of hypertension and obesity, which make it a sensible candidate gene for type 2 diabetes. To assess the influence of GNB3 in type II diabetes mellitus (NIDDM), we carried out a retrospective, case-control study of variant GNB3 825C>T for putative correlations with NIDDM amongst nationals from the United Arab Emirates (Emirati) - an ethnic group characterized by no alcohol intake and no cigarette smoking. We investigated a sample population of 510 Emirati (257 men, 253 women) comprising two groups - 254 controls and 256 patients with clinical diagnoses of type 2 diabetes (cases). The GNB3 C825T dimorphism showed an association with NIDDM Chi2 =22.5, 2 df, P<0.001). Further analysis revealed that the GNB3 T/T 825 genotype was positively associated with NIDDM (Yates corrected Chi2=20.6, 2 df, P<0.001; odds ratio of 2.44 with a 95% confidence interval of 1.64 - 3.63) compared to pooled CC/CT genotypes. Our data shows that GNB3 T825 allele may be involved in the pathogenesis of DM through a pathway that is different from the one implicated in obesity.

Lack of association of methylenetetrahydrofolate reductase 677C>T mutation with coronary artery disease in a Pakistani population.

Pakistanis belong to the South Asian population which has the highest known rate of coronary artery disease. Folic acid deficiency also appears to be highly prevalent in this population. Methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism decreases the activity of this enzyme and can be associated with mild to moderate hyperhomocysteinemia in homozygotes, particularly when there is folic acid deficiency, as well as with coronary artery disease. To assess the value of genotyping the MTHFR 677C>T dimorphism, we carried out a case-control study of dimorphism 677C>T for putative association with myocardial infarction (MI) among Pakistani nationals. We investigated a sample population of 622 Pakistanis consisting of 225 controls and 397 patients with clinical diagnosis of acute MI (AMI). MTHFR C677T alleles were determined by assays based on polymerase chain reaction and restriction endonuclease analysis. Frequencies of C alleles were 0.87 among controls and 0.86 among AMI patients. The MTHFR 677C>T dimorphism showed no association with MI (chi(2) = 0.25, 1df, P=0.62), serum levels of folate and vitamin B12 and plasma level of vitamin B6. A significant association, however, was found between homozygous 677T genotype and plasma levels of homocysteine. Multivariate analysis of the data showed that in case of log homocysteine, age and MTHFR genotypes were significantly different (P<0.001). In case of B12, smoking and age were found to be statistically significant (P<0.001), while in case of serum folate only smoking was found to be significant (P<0.001). The results indicate that MTHFR 677C>T polymorphism, though associated with homocysteine levels, confers no significant risk of coronary artery disease in the Pakistani population investigated here. We suggest that the higher incidence of AMI in South Asia occurs through mechanisms other than the MTHFR related pathways.

G-protein beta-3 subunit gene 825C>T dimorphism is associated with left ventricular hypertrophy but not essential hypertension.

BACKGROUND: The human G-protein beta 3 subunit gene (GNB3) and some of its variants are known to be important genetic influences involved in essential hypertension (EH). Left ventricular hypertrophy (LVH) has long been thought to be an end point of EH, rather than a separate entity, though it is influenced by a unique set of hormonal, vascular and genetic factors. METHODS/MATERIALS: We carried out a retrospective, case-control study of a GNB3 825 C>T dimorphism among nationals from the United Arab Emirates (Emirati), an ethnic group characterized by no alcohol intake and no cigarette smoking, for putative correlations with EH and LVH. We investigated a sample population of 454 Emirati (231 men, 223 women) comprising groups of controls and patients with clinical diagnoses of LVH, based on echocardiographic and ECG criteria, and EH, based on blood pressure values. The GNB3 825 C>T genotypes were determined by PCR and restriction digestion. RESULTS: The distribution of genotypes was in Hardy-Weinberg equilibrium in all three subject groups. GNB3 T825 alleles demonstrated a strong association with LVH (OR = 2.22; 95% CI: 1.29-3.83 and P = 0.0002), but not with EH. CONCLUSIONS: GNB3 825 C>T is likely to be a significant risk factor for LVH but not for EH in the Emirati population, thereby strengthening the view that LVH is genetically a separate clinical entity.

Head and neck cancer susceptibility: a genetic marker in the methylenetetrahydrofolate reductase gene.

Progress in the elucidation of molecular genetic changes that lead to the development of tumors should soon bring novel diagnostic and therapeutic procedures into clinical practice. In this respect, methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism that affects DNA methylation and synthesis. DNA methylation is an epigenetic feature that influences cellular development and function. Germ line mutation C>T at nucleotide 677 of the MTHFR gene, which results in increased thermolability and diminished enzyme activity, is oncogenic, i.e. should be a contributor to molecular changes leading to cancerous phenotypes (it has also been shown independently to be implicated in cardiovascular disease phenotypes). Interestingly, it has been shown that MTHFR T677 allele homozygosity confers a sixfold increased risk for esophageal squamous cell carcinoma in Northern China. The purpose of this study was twofold: (1) to evaluate the putative association of MTHFR C677T and epithelial squamous cell carcinoma (ESCC) in Pakistan, and (2) to investigate whether de novo MTHFR C677T mutations are involved in the determination of ESCC phenotypes. We recruited 50 ESCC patients referred to the Otolaryngology Clinic of the Aga Khan University Hospital, and 54 age- and gender-matched control (disease-free) subjects. Our results show that T allele frequencies were 0.18 +/- 0.05 in cases vs. 0.24 +/- 0.05 in controls (as compared with 0.63 vs. 0.41 in the report from China). Although the association is not statistically significant, T alleles are actually more common amongst controls in the Pakistani population, which is the opposite of what would be expected and what has been reported amongst Chinese. Yet the frequency of deleterious T alleles is lower in Pakistan (range 0.18-0.24) than in other parts of the world. Our results indicate that MTHFR C677T cannot form the basis for a genetic test aimed at evaluating an individual's genetic susceptibility to ESCC in Pakistan. As the conversion of precancerous submucous fibrosis into overt cancer is a frequent occurrence in Pakistan, we proceeded to extract DNA samples in all ESCC patients, from whole blood, cancerous tissues and neighboring normal tissues. We sought to determine whether C677T genotypes were different in the three tissue samples from each ESCC patient. In all patients, identical genotypes (and therefore allele frequencies) were systematically observed in all three samples. This indicates that de novo MTHFR 677TC>T mutations are not part of the molecular etiology of ESCC. In conclusion, we can rule out a major involvement of the MTHFR gene in the determination of ESCC in Pakistan.

Xeroderma pigmentosum in four siblings with three different types of malignancies simultaneously in one.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease characterized by marked sensitivity to ultraviolet radiation that leads to the development of multiple skin malignancies. The authors describe four XP siblings in a consanguineous Pakistani family. The first patient was a boy who died at age 2 years. The second and third siblings were girls who died at age 2 and 7 years, respectively. The fourth sibling, the propositus, was a boy diagnosed with XP at age 7 years. He developed three different types of malignancies simultaneously and died at age 13. The authors conclude that it is important to be aware of multiple malignancies of different types in the same patient with XP.

Mal de Meleda (MDM) caused by mutations in the gene for SLURP-1 in patients from Germany, Turkey, Palestine, and the United Arab Emirates.

Mal de Meleda (MDM) or keratosis palmoplantaris transgrediens of Siemens is an autosomal recessive skin disorder characterized by diffuse palmoplantar keratoderma (PPK) and transgressive keratosis with an onset in early infancy. There is no associated involvement of other organs; however, a spectrum of clinical presentations with optional and variable features has been described. Mutations in the ARS (component B)-81/s gene ( LY6LS) on chromosome 8q24-qter, which encodes SLURP-1, have recently been identified in patients with MDM. Here, we have analyzed four MDM families for mutations in SLURP-1. In a large Palestinian pedigree with multiple consanguinity, patients are homozygous for a new mutation that substitutes an arginine for a conserved glycine residue at position 86. A different mutation in Turkish patients results in the same amino acid exchange. Some remarkable similarities are seen in the clinical picture of patients from both families. Patients of an Emirati Bedouin family have a homozygous alteration of the translation initiation codon. In a German family with no known consanguinity, we have shown pseudodominant inheritance. Three affected children and their affected mother are homozygous for the missense mutation W15R. Our findings indicate that the MDM type of transgressive PPK is caused by SLURP-1 mutations in patients from various origins and demonstrate allelic heterogeneity for mutations in SLURP-1.

A study of five human cytokine genes in human essential hypertension.

With a view to evaluating the putative involvement of cytokine gene variants in human essential hypertension, we carried out an association (case-control) study on 174 unrelated nationals (81 hypertensives and 93 normotensives) from the Abu Dhabi Emirate (UAE), a genetically homogeneous population also characterised by the absence of traditional confounding factors such as alcohol consumption and smoking. To that end, we targeted our investigation to five candidate gene loci-transforming growth factor beta1 (TGF-beta1), interferon gamma (IFN-gamma), epidermal growth factor (EGF), interleukin-1 beta (IL-1beta) and tumour-necrosis factor (TNF-alpha) genes. We investigated the distribution of genotypes and alleles of the six following dimorphic variants: TGF-beta1(*)10(T>C) and TGF-beta1(*)25(G>C), located at codons 10 and 25, respectively, of TGF-beta1; T874A in intron 1 of IFN-gamma; G61A in exon 1 of EGF; TaqI dimorphism at +3962 (exon 5) of IL-1beta; and -308A>G in the promoter of TNF-alpha. These six bi-allelic markers were visualised by methods based on the techniques of amplification refractory mutation system-polymerase chain reaction (for TGF-beta1, IFN-gamma, EGF and TNF-alpha) and by polymerase chain reaction-TaqI restriction endonuclease analysis in the case of IL-1beta. In each of the two groups (normotensives and hypertensives), genotype frequencies of all six markers occurred in Hardy-Weinberg proportions. There were, however, no statistical differences in the allele and genotype frequencies of any of the six markers between the two groups of subjects: TGF-beta1(*)10C frequencies were 0.46 and 0.49 (chi(2)=0.61; 2 d.f.; P=0.74) and TGF-beta1(*)25C were 0.07 and 0.08 (chi(2)=0.61; 2 d.f.; P=0.74) amongst normotensives and hypertensives, respectively; p(IFN-gamma(*)A874) were 0.41 in normotensives versus 0.46 in hypertensives (chi(2)=3.07; 2 d.f.; P=0.22); p(EGF (*)G61) were 0.51 versus 0.58 (chi(2)=1.76; 2 d.f.; P=0.41); p[IL-1beta (*)TaqI(+)] were 0.43 versus 0.36 (chi(2)=2.08; 2 d.f.; P=0.35); and p(TNF-alpha(*)-308G) were 0.80 versus 0.85 (chi(2)=1.29; 2 d.f.; P=0.53). There was also no difference in distribution and frequencies of haplotypes constructed with combinations of TGF-beta1(*)10(T>C) and TGF-beta1(*)25(G>C) sites. However, although they do not reach statistical significance (which may be due to the relatively restricted number of subjects included in this study), the distribution differences (in normotensives and hypertensives) observed in the cases of EGF and TNF-alpha reflect trends that could be expected from a mechanistic explanation of the pathways that underlie the patho-physiology of hypertension.

Junctional epidermolysis bullosa in the Middle East: clinical and genetic studies in a series of consanguineous families.

BACKGROUND: Junctional epidermolysis bullosa (JEB) is a group of inherited blistering diseases characterized by epidermal-dermal separation resulting from mutations that affect the function of critical components of the basement membrane zone. This group of autosomal recessive diseases is especially prevalent in regions where consanguinity is common, such as the Middle East. However, the clinical and genetic epidemiology of JEB in this region remains largely unexplored. OBJECTIVE: The aim of the present study was to assess a series of consanguineous JEB families originating from the Middle East. METHODS: We identified 7 families referred to us between 1998 and 1999 and originating from the United Arab Emirates, Saudi Arabia, Sudan, Yemen, and Israel. Histologic, immunofluorescence, and electron microscopy studies were performed to direct the subsequent molecular analysis. DNA obtained from all family members was amplified by means of polymerase chain reaction and analyzed by conformation-sensitive gel electrophoresis with subsequent direct sequencing. RESULTS: In 6 families presenting with the clinical and histologic features distinctive for JEB, mutations in genes encoding 1 of the 3 subunit polypeptides of laminin-5 were identified. Two families each had mutations in LAMB3, 2 in LAMA3, and 2 in LAMC2. Out of 7 distinct mutations, 5 were novel and 2 were recurrent. No relationship was found between the presence of nonsense/frameshift mutations in laminin-5 genes and perinatal mortality, contradicting a major genotype-phenotype correlation previously reported in the European and US literature. Similarly, none of the recurrent LAMB3 hot spot mutations previously described in other populations was found in our series. Finally, in a family with the clinical diagnosis of generalized atrophic benign epidermolysis bullosa, a homozygous non-sense mutation in Col17A1 gene (encoding the BPAG2 antigen) was identified. CONCLUSION: The present report suggests (1) the existence of a unique spectrum of mutations in the Middle East populations and (2) the need for the implementation of a diagnostic strategy tailored to the genetic features of JEB in this region.