Mutations in ERGIC1 cause Arthrogryposis multiplex congenita, neuropathic type.

Arthrogryposis multiplex congenita (AMC) is heterogeneous group of disorders characterized by non-progressive joint contractures from birth that involve more than 1 part of the body. There are various etiologies for AMC including genetic and environmental depends on the specific type, however, for most types, the cause is not fully understood. We previously reported large Israeli Arab kindred consisting of 16 patients affected with AMC neuropathic type, and mapped the locus to a 5.5 cM interval on chromosome 5qter. Using whole exome sequencing, we have now identified homozygous pathogenic variant in the ERGIC1 gene within the previously defined linked region. ERGIC1 encodes a cycling membrane protein which has a possible role in transport between endoplasmic reticulum and Golgi. We further show that this mutation was absent in more than 200 samples of healthy unrelated individuals of the Israeli Arab population. Thus, our findings expand the spectrum of hereditary AMC and suggest that abnormalities in protein trafficking may underlie AMC-related disorders.

Founder mutation for Huntington disease in Caucasus Jews.

Huntington disease (HD), an autosomal dominant disorder involving HTT, is characterized by chorea, psychiatric illness and cognitive decline. Diagnosis and age of onset depend on the degree of expansion of the trinucleotide CAG repeat within the gene. The prevalence of HD is known for Europeans but has not been studied in the Israeli population. Between 2006 and 2011 we diagnosed in our adult genetics clinic ten HD probands, nine of whom were Caucasus Jews (CJ) (Azerbaijani), and one Ashkenazi Jewish. We performed haplotype analysis to look for evidence of a founder mutation, and found that of the nine CJ, eight shared the same haplotype that was compatible with the A1 haplogroup. We calculated the coalescence age of the mutation to be between 80 and 150 years. Ninety percent of our HD patients are CJ, as are 27% of the HD patients in Israel, although the CJ comprise only 1.4% of the Israeli population. Our findings suggest a higher prevalence of HD among CJ compared to the general Israeli population and are consistent with a recent founder mutation. We recommend a higher degree of suspicion for HD in CJ with subtle clinical findings.

High frequency of autosomal-recessive DFNB59 hearing loss in an isolated Arab population in Israel.

Autosomal-recessive non-syndromic hearing impairment (DFNB) is usually of prelingual onset with a moderate to profound degree of hearing loss. More than 70 DFNB loci have been mapped and ~40 causative genes have been identified. Non-syndromic hearing impairment caused by mutations of DFNB59 (encoding pejvakin) has been described in a couple of families in which affected individuals presented with either auditory neuropathy or hearing loss of cochlear origin. We have identified and clinically evaluated three consanguineous families of Israeli Arab origin with prelingual non-syndromic hearing impairment and absent otoacoustic emissions in a total of eight affected individuals. All the families originate from the same village and bear the same family name. We have identified a c.406C>T (p.R136X) nonsense mutation in the DFNB59 gene in affected individuals from these families. Among the inhabitants of the village, we found an exceptionally high carrier frequency of ~1 in 12 individuals (7/85; 8.2%). The high prevalence of hearing impairment can be explained by a founder effect and the high consanguinity rate among the inhabitants of this village.

Autosomal recessive ichthyosis with hypotrichosis syndrome: further delineation of the phenotype.

Autosomal recessive ichthyosis with hypotrichosis (ARIH) syndrome, which is characterized by congenital ichthyosis, abnormal hair and corneal involvement, has recently been shown in one consanguineous Israeli Arab family to be caused by a mutation in the ST14 gene, which encodes serine protease matriptase. No other families have so far been described since the original report. In this current report we describe a female patient from a second family with ARIH syndrome who carries a homozygous novel mutation, p.M1I. The patient has congenital ichthyosis, light brown, curly, sparse hair, improving with age, and sparse body hair, eyebrows and eyelashes. She does not suffer from photophobia, but has blepharitis. The phenotype of this patient closely resembles that of the affected individuals in the previously reported family, although she does not have tooth abnormalities and the ichthyosis is milder.

The CC2D1A, a member of a new gene family with C2 domains, is involved in autosomal recessive non-syndromic mental retardation.

BACKGROUND: The molecular basis of autosomal recessive non-syndromic mental retardation (NSMR) is poorly understood, mostly owing to heterogeneity and absence of clinical criteria for grouping families for linkage analysis. Only two autosomal genes, the PRSS12 gene on chromosome 4q26 and the CRBN on chromosome 3p26, have been shown to cause autosomal recessive NSMR, each gene in only one family. OBJECTIVE: To identify the gene causing autosomal recessive NSMR on chromosome 19p13.12. RESULTS: The candidate region established by homozygosity mapping was narrowed down from 2.4 Mb to 0.9 Mb on chromosome 19p13.12. A protein truncating mutation was identified in the gene CC2D1A in nine consanguineous families with severe autosomal recessive NSMR. The absence of the wild type protein in the lymphoblastoid cells of the patients was confirmed. CC2D1A is a member of a previously uncharacterised gene family that carries two conserved motifs, a C2 domain and a DM14 domain. The C2 domain is found in proteins which function in calcium dependent phospholipid binding; the DM14 domain is unique to the CC2D1A protein family and its role is unknown. CC2D1A is a putative signal transducer participating in positive regulation of I-kappaB kinase/NFkappaB cascade. Expression of CC2D1A mRNA was shown in the embryonic ventricular zone and developing cortical plate in staged mouse embryos, persisting into adulthood, with highest expression in the cerebral cortex and hippocampus. CONCLUSIONS: A previously unknown signal transduction pathway is important in human cognitive development.

Infantile bilateral striatal necrosis maps to chromosome 19q.

BACKGROUND: Infantile bilateral striatal necrosis (IBSN) encompasses several syndromes of bilateral symmetric degeneration of the caudate nucleus, putamen, and globus pallidus. Autosomal recessive IBSN is characterized clinically by developmental arrest beginning at age 7 to 15 months, dysphagia, choreoathetosis, pendular nystagmus and optic atrophy, and severe progressive atrophy of the basal ganglia on MRI. OBJECTIVE: To map the gene causing IBSN. METHODS: A 10-cM genome-wide linkage scan was initially performed on five affected and five unaffected individuals. The extended family was included in the analysis to narrow the candidate region. Logarithm of odds (LOD) score was calculated using the SUPERLINK program. RESULTS: Linkage to the chromosomal region 19q13.32-13.41 was established (Z(max) = 6.27 at theta = 0.02 at locus D19S412). Recombination events and a common disease-bearing haplotype defined a critical region of 1.2 Mb between the loci D19S596 proximally and D19S867 distally. CONCLUSION: IBSN maps to the chromosomal region 19q13.32-13.41. The presence of a common haplotype in all the patients suggests that the disease is caused by a single mutation derived from a single ancestral founder in all the families.

Mapping of a new locus for autosomal recessive non-syndromic mental retardation in the chromosomal region 19p13.12-p13.2: further genetic heterogeneity.

OBJECTIVE: To identify and clinically evaluate four consanguineous families of Israeli Arab origin with non-syndromic mental retardation (NSMR), comprising a total of 10 affected and 24 unaffected individuals. PARTICIPANTS AND METHODS: All the families originated from the same small village and had the same family name. Association of the condition in these families with the two known autosomal recessive NSMR loci on chromosomes 3p25-pter and 4q24 (neurotrypsin gene) was excluded. RESULTS: Linkage of the disease gene to chromosome 19p13.12-p13.2(Zmax = 7.06 at theta = 0.00) for the marker D19S840 was established. All the affected individuals were found to be homozygous for a common haplotype for the markers cen-RFX1-D19S840-D19S558-D19S221-tel. CONCLUSIONS: The results suggest that the disease is caused by a single mutation derived from a single ancestral founder in all the families. Recombination events and a common disease bearing haplotype defined a critical region of 2.4 Mb, between the loci D19S547 proximally and D19S1165 distally.

Replicative senescence in organ transplantation-mechanisms and significance.

In the past two decades, transplantation has become a preferred modality of treatment of end-stage failure of vital organs. Currently, with the significant improvement in short-term graft survival rates, the main effort is concentrated on prolonging the functional life span of transplanted organs. One of the theories which were put forward to explain the progressive deterioration of transplant function was that of replicative senescence. Senescence of an organ or tissue results from age and/or environmental stress-dependant modification of cellular function. With time, the accumulation of cellular alterations may lead to deleterious effects in various organs and tissues and adversely affect transplants. In this article we are reviewing the candidate mechanisms of senescence such as telomere shortening, genetic regulation and environmental-'toxic' factors and are examining the implications of the theory of replicative senescence for organ allograft. We are also presenting our experiments with renal ischemia/reperfusion in rat serving as a model of kidney transplantation, where baseline kidney telomere length and novel marker of cellular senescence--senescence associated beta-Galactosidase (SA-Gal) expression in tissue served as markers. For the first time in vivo, we were able to show that with aging of the animals the amount of senescent cells in kidney tissue was increasing, while the average renal tissue telomere length was decreasing. The degree of tissue senescence, as determined by amount of SA-Gal positively stained cells, was inversely correlated with the recovery of the kidney function after ischemia/reperfusion injury. These results confirm the theory of replicative senescence in organ ischemia for the first time in vivo, and quantitatively validate the direct correlation between the amount of senescent cells in the organ and its susceptibility to ischemic injury. We conclude that recent advances in study of the cellular basis of senescence, in vitro and especially in vivo, may hold clues to the understanding of events which could be implicated in the damage or protection of organ allografts.

Fine mapping places the gene for arthrogryposis multiplex congenita neuropathic type between D5S394 and D5S2069 on chromosome 5qter.

Arthrogryposis multiplex congenita (AMC) is a heterogeneous symptom complex characterized by non-progressive joint contractures from birth that involve more than one part of the body. In 1997, our group investigated a large Israeli Arab inbred kindred that showed autosomal recessive inheritance of AMC neuropathic type, and we mapped the gene to 5qter between markers D5S1456 and D5S498. Haplotype sharing studies revealed complete homozygosity in all affected individuals with marker D5S394, thus providing significant statistical evidence in favor of linkage. In this study, we have undertaken further fine mapping of this region of chromosome 5qter, and have examined several additional markers. All the affected individuals showed complete homozygosity for the marker D5S394, and also for three additional markers that are telomeric to marker D5S394 and situated 31766 bp, 58016 bp, and 58516 bp, respectively, from it. Analysis of the recombinant individuals has enabled us to narrow down the critical region to a distance of.442 Mb between markers D5S394 and D5S2069.

Fragile-X carrier screening and the prevalence of premutation and full-mutation carriers in Israel.

Fragile-X syndrome is caused by an unstable CGG trinucleotide repeat in the FMR1 gene at Xq27. Intermediate alleles (51-200 repeats) can undergo expansion to the full mutation on transmission from mother to offspring. To evaluate the effectiveness of a fragile-X carrier-screening program, we tested 14,334 Israeli women of child-bearing age for fragile-X carrier status between 1992 and 2000. These women were either preconceptional or pregnant and had no family history of mental retardation. All those found to be carriers of premutation or full-mutation alleles were offered genetic counseling and also prenatal diagnosis, if applicable. We identified 207 carriers of an allele with >50 repeats, representing a prevalence of 1:69. There were 127 carriers with >54 repeats, representing a prevalence of 1:113. Three asymptomatic women carried the fully mutated allele. Among the premutation and full-mutation carriers, 177 prenatal diagnoses were performed. Expansion occurred in 30 fetuses, 5 of which had an expansion to the full mutation. On the basis of these results, the expected number of avoided patients born to women identified as carriers, the cost of the test in this study (U.S. $100), and the cost of lifetime care for a mentally retarded person (>$350,000), screening was calculated to be cost-effective. Because of the high prevalence of fragile-X premutation or full-mutation alleles, even in the general population, and because of the cost-effectiveness of the program, we recommend that screening to identify female carriers should be carried out on a wide scale.

Autosomal dominant nephritis with renal failure of non-Alport type: clinical and molecular studies.

BACKGROUND: Familial nephritis is a heterogeneous group of disorders caused by several genetic conditions such as Alport syndrome, glomerulonephritic syndromes, and unclassified nephritis without deafness or ocular defects. OBJECTIVES: To describe a family of Iraqi Jewish origin, several of whose members suffer from non-syndromic renal failure without deafness or ocular defects and where transmission is by autosomal dominant inheritance. We present the case histories of four family members and describe the molecular analysis performed in order to seek a possible linkage to one of the genes causing Alport or Alport-like syndromes. METHODS: We investigated all family members over the age of 18 for evidence of renal failure. We also extracted DNA and carried out molecular linkage analysis with polymorphic markers in each of the known loci involved in Alport and Alport-like syndromes. RESULTS: Histology of the renal biopsy specimens showed non-specific findings. Linkage was excluded for all the Alport and Alport-like syndrome loci. CONCLUSIONS: The condition suffered by several members of this family seems to represent a unique autosomal dominant type of progressive hereditary nephritis, characterized by hypertension and progressive renal failure without significant hematuria or proteinuria. The main histological changes are non-specific in the early stage of the disease. Our study rules out all the currently known genes that cause Alport syndrome as being responsible for the basic defect in this type of nephritis.

Renal outcome and vascular morbidity in systemic lupus erythematosus (SLE): lack of association with the angiotensin-converting enzyme gene polymorphism.

OBJECTIVES: The angiotensin-converting enzyme (ACE) gene polymorphism has been associated with worse outcome in various chronic glomerular disorders and in hypertension. Because nephritis and vascular morbidity are prominent determinants of outcome in systemic lupus erythematosus (SLE), we studied the distribution and prognostic effect the ACE genotype might have on the outcome of SLE. METHODS: Fifty-six consecutive Israeli SLE patients and 48 (sex and ethnic origin matched) healthy individuals were evaluated for the ACE genotype by a polymerase chain reaction-based assay. The clinical and laboratory parameters of the patients as well as the SLE disease activity index (SLEDAI) and the presence of hypertension, diabetes mellitus, ischemic heart disease, congestive heart failure, and stroke were correlated with the ACE genotype. RESULTS: The distribution of the ACE genotype D/D, D/I, and I/I in the lupus group was 59%, 36%, and 5%, respectively, similar to the distribution in the control group (54%, 31%, and 15%, respectively). We failed to find any significant association between the ACE genotype and disease manifestations, SLEDAI, renal function, or cardiovascular and cerebrovascular morbidity. The clinical and laboratory parameters associated with renal outcome and vascular morbidity in our cohort are described. CONCLUSIONS: No difference was found between the distribution of the ACE genotype in lupus patients and the general population in Israel. Renal function as well as cardiovascular and cerebrovascular morbidity among Israeli patients with SLE are disease-related and independent of the ACE gene polymorphism.

Higher than expected carrier rates for familial Mediterranean fever in various Jewish ethnic groups.

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent attacks of inflammation of serosal membranes. Amyloidosis leading to renal failure is the most severe complication in untreated patients. In Israel FMF is most frequent among Jews of North African origin. Recently the causative gene (MEFV) has been found and the common mutations characterised. The aim of this study was to investigate the carrier rates of the common MEFV mutations among 400 healthy members of four different ethnic groups (100 in each group) in Israel, and to compare the distribution of the different mutations between FMF carriers and patients. We found a high frequency of carriers among Jews from the various ethnic groups. In North African Jews it was 22%, in Iraqi Jews 39%, in Ashkenazi Jews 21%, and in Iranian Jews 6%. The distribution of the four most common MEFV mutations among healthy individuals (M694V 29%, V726A 16%, M6801 2% and E148Q 53%) was significantly different (P < 0.003) from that found in patients (M694V 84.4%, V726A 9.0%, M6801 0% and E148Q 6.6%). Six healthy asymptomatic individuals were found to carry mutations in both alleles: two homozygotes for E148Q and four compound heterozygotes E148Q/other. These results demonstrate a very high carrier rate among all Jewish ethnic groups. They confirm that mutation E148Q is associated with a milder phenotype, which explains the lower prevalence of FMF among the Ashkenazi and Iraqi Jews. This study raises the question of the need for molecular screening for M694V homozygotes in the Israeli North African Jewish community.

Increased transmission of intermediate alleles of the FMR1 gene compared with normal alleles among female heterozygotes.

Fragile X syndrome (Fra X) is the most common heritable disease accounting for mental retardation and is caused by an expanded CGG repeat in the first exon of the FMR1gene. Previous studies have shown an increased fertility rate among fragile X carrier mothers and a preponderance of mentally retarded boys among the male offspring. In this study, we examined the transmission of the intermediate allele in the lower range of CGG repeats in carrier mothers found randomly in a screening program of the normal population. We tested 10,587 healthy women with no family history of mental retardation and identified 138 (1.3%) who were carriers of the intermediate allele (51-200 CGG repeats). Of these, 107 underwent prenatal testing during 108 pregnancies for Fra X in the fetus. Of the 108 pregnancies, the abnormal allele was transmitted in 67 (segregation ratio = 0.62, P < 0.012). We found a significant increase in the transmission of the abnormal allele by mothers who had between 51 and 60 repeats (segregation ratio = 0.69 [P < 0.007] for the group with 51-55 repeats, and 0.74 [P < 0.04] for the group with 56-60 repeats), but no increase by mothers who had more than 61 repeats. This suggests a genetic advantage for the abnormal allele in the 51- to 60-repeat range.

Familial Mediterranean fever: effects of genotype and ethnicity on inflammatory attacks and amyloidosis.

OBJECTIVE: The gene causing familial Mediterranean fever (FMF)-an autosomal recessive disease characterized by recurrent short episodes of fever associated most commonly with peritonitis, pleuritis, and arthritis-has recently been found and several mutations identified. The most severe complication of the disease is amyloidosis, which can lead to renal failure. The aim of this study was to investigate the role of genetic versus nongenetic factors on the phenotype as well as on the development of amyloidosis in FMF in a large and heterogeneous group of patients. METHODOLOGY: We studied 382 patients from 4 ethnic origins living in different environments: North African Jews, other Jews, Turks, Armenians living in the United States, and Armenians from Yerevan, Armenia. Information regarding amyloidosis was available for 371 patients. We examined the association between the mutation M694V and the development of amyloidosis, and we also compared the clinical characteristics of the inflammatory attacks in patients from different ethnic origins, while controlling for the type of mutation. RESULTS: A significant association was found between amyloidosis and the most common mutation in exon 10 of the FMF gene (MEFV), M694V (for M694V homozygotes, relative risk = 1.77; 95% CI = 1.16-2.71). Amyloidosis was present in 44 of 171 homozygous FMF patients (25.7%), in 22 of 143 compound heterozygous FMF patients (15.4%), and in 7 of 57 patients carrying other mutations (12.3%). In homozygotes for M694V who had not been treated with colchicine before 20 years of age, the risk of amyloidosis developing before this age was 61.0%. In our series, there were no cases of amyloidosis in 16 patients carrying the common mutation E148Q. We found that the type and severity of the FMF inflammatory symptoms were associated with both the genotype and the country of residence of the patient. CONCLUSIONS: In the light of the high frequency of amyloidosis in homozygotes for the mutation M694V, colchicine treatment should be given to this group irrespective of the severity of the inflammatory attacks to prevent the development of amyloidosis. Our findings also suggest that factors other than genotype, such as environment or genes other than MEFV, play a role in the determination of the severity of the inflammatory attacks in FMF. amyloidosis, specific mutation, phenotype-genotype correlation, ethnicity.

Methylenetetrahydrofolate reductase genotypes and early-onset coronary artery disease.

BACKGROUND: Homozygosity for the common (677C-->T) mutation in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with hyperhomocysteinemia, but there is uncertainty as to the association between this mutation and coronary artery disease (CAD). This study examined the association between MTHFR genotypes and age at onset of CAD. METHODS AND RESULTS: Patients (n=169) with documented myocardial infarction or angiographically documented CAD who were aged < or = 55 years at onset of CAD symptoms and DNA samples from control subjects (n=313) were studied. The prevalence of homozygosity among patients with early CAD onset (aged < or = 45 years) was 28%, which was significantly higher than that in patients with later onset (13%) and in control subjects (14%) (odds ratio 2.4, 95% CI 1.24 to 4.69, P=0.006, and odds ratio 2.7, 95% CI 1.15 to 6.42, P=0.01, respectively). Plasma folate was lower in TT homozygotes who had early CAD onset than in those with later onset (P=0.005). Among patients with plasma folate in the lowest quintile (< or = 12.6 nmol/L), 31% were homozygotes, as were 45% of those with low plasma folate and early CAD onset. There was no difference in the prevalence of traditional risk factors among genotypes. The frequency of homozygosity in patients with < or = 1 risk factor was higher than in those with > or = 2 risk factors (30% versus 12%, P<0.05). In multiple regression analysis, TT homozygosity and plasma folate were independently associated with CAD, but the impact of folate was small. CONCLUSIONS: Homozygosity for the 677C-->T mutation of MTHFR is common and is associated with an increased risk of premature CAD in this population.

Phenotype-genotype correlation in familial Mediterranean fever: evidence for an association between Met694Val and amyloidosis.

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterised by recurrent attacks of inflammation of serosal membranes. Amyloidosis is the most severe complication of the disease. The aim of this study was to investigate the genotype-phenotype correlation and specifically the association between amyloidosis and the four common mutations in exon 10 of the gene causing FMF (MEFV) in a total of 83 FMF families from three ethnic groups: North African Jews, Armenians and Turks. A significant association was found between amyloidosis and the specific mutation at the MEFV gene: Met694Val (RR = 1.41, P = 0.02). Amyloidosis was present in 18 out of 87 homozygous FMF patients (20.7%) and in only two out of the 41 compound heterozygous FMF patients (4.9%). No patients carrying other mutations had amyloidosis. There was no significant association between the various mutations and the type or severity of the FMF symptoms. This finding underscores the importance of performing molecular studies on all suspect FMF patients. In addition to providing accurate diagnosis, these tests allow identification of presymptomatic genetically affected individuals, detection of carriers and assessment of the risk for amyloidosis in later life.

A novel allele in the promoter region of the human serotonin transporter gene.

The human serotonin transporter (hSERT) gene is a promising candidate for mediating the genetic susceptibility for various psychiatric conditions such as mood and obsessive-compulsive disorders. Two polymorphic sites in this gene attracted much interest: a VNTR of 17-bp repeats in intron two, and an insertion/deletion in the 5'-flanking promoter region (5-HTT gene-linked polymorphic region-5-HTTLPR) creating a short (S) and a long (L) allele. The 5-HTTLPR polymorphism is situated in a GC-rich region composed of 20-23 bp repeating units. The S and L alleles have 14 and 16 repeat-elements respectively. Positive associations of the 5-HTTLPR polymorphism with mood disorders, anxiety-related personality traits, autism and late-onset Alzheimer's disease have been published, although some non replications were also reported. Here we report a novel allele (termed LJ) in the 5-HTTLPR site. This allele is longer than the L allele by 43 bp, has 18 repeat units and contains two copies of the insertion/deletion sequence arranged in tandem. The LJ allele was found in individuals of Libyan and Tunisian Jewish origin but not in Moroccan or Ashkenazi Jews.

Amyloidosis in familial mediterranean fever is associated with a specific ancestral haplotype in the MEFV locus.

Familial Mediterranean fever (FMF) is a recessive disease characterized by recurrent attacks of inflammation of serosal membranes, and the gene responsible, MEFV, has been recently identified. Amyloidosis is considered to be the most severe complication. Since colchicine is effective in preventing FMF amyloidosis and since this process can develop even prior to the FMF symptoms, lifelong colchicine treatment is recommended for all FMF patients. Identification of the factor which determines amyloidosis will allow treatment to be directed only to those at risk. In order to investigate the association between amyloidosis and MEFV haplotypes, we studied 56 families from three ethnic groups. We compared the haplotypes of FMF patients with and without amyloidosis in each ethnic group separately and identified 14 different MEFV core haplotypes. A significant association (P < 0.004) was found between amyloidosis and a specific core haplotype, 153bp:104bp at markers D16S3370 and D16S2617, respectively. Amyloidosis was present in 20 out of 70 homozygotes for this haplotype and in 6 out of 35 compound heterozygotes for this and other core haplotypes. None of the patients who did not carry this allele had amyloidosis. There was no association between the various haplotypes and severity of the FMF symptoms, age of onset, or age at commencement of colchicine. Further investigation of the MEFV haplotypes in additional patients is recommended as such an association may save many mildly affected or asymptomatic patients with non-amyloidotic genotypes from receiving unnecessary lifelong colchicine treatment.