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.

Homozygous deletion of RAG1, RAG2 and 5' region TRAF6 causes severe immune suppression and atypical osteopetrosis.

Mutations of several genes have been implicated in autosomal recessive osteopetrosis (OP), a disease caused by impaired function and differentiation of osteoclasts. Severe combined immune deficiencies (SCID) can likewise result from different genetic mutations. We report two siblings with SCID and an atypical phenotype of OP. A biallelic microdeletion encompassing the 5' region of TRAF6, RAG1 and RAG2 genes was identified. TRAF6, a tumor necrosis factor receptor-associated family member, plays an important role in T cell signaling and in RANKL-dependent osteoclast differentiation and activation but its role in human OP has not been previously reported. The RAG proteins are essential for recombination of B and T cell receptors, and for the survival and differentiation of these cells. This is the first study to report a homozygous deletion of TRAF6 as a cause of human disease.

Cut-off value of nuchal translucency as indication for chromosomal microarray analysis.

OBJECTIVES: An association between isolated, increased nuchal translucency thickness (NT) and pathogenic findings on chromosomal microarray analysis (CMA) has been reported. A recent meta-analysis reported that most studies use a NT cut-off value of 3.5 mm. However, considering NT distribution and the commonly accepted 5% false-positive rate in maternal serum screening, NT cut-off levels should be reconsidered. The aim of this study was to assess different NT cut-off levels as indication for CMA and to determine whether CMA should be recommended for mildly increased NT of 3.0-3.4 mm. METHODS: This was a retrospective, multicenter study of singleton pregnancies with CMA results and either normal NT and no other finding or with increased NT as the only medical indication for CMA at the time of an invasive procedure (increased NT was considered an isolated finding in cases of advanced maternal age). Women with normal fetal NT who underwent CMA did so at their own request. A single laboratory performed all genetic analyses. Comparative genomic hybridization microarray analysis or single nucleotide polymorphism array technology was used for CMA. If combined first-trimester screening (NT and biochemistry) indicated increased risk for common aneuploidies, the case was excluded. NT was used to divide cases into three groups (≤ 2.9 mm, 3.0-3.4 mm and ≥ 3.5 mm) and their CMA results were compared. RESULTS: CMA results were recorded in 1588 pregnancies, among which 770 fetuses had either normal NT with no other finding or isolated increased NT. Of these, 462 had NT ≤ 2.9 mm, 170 had NT of 3.0-3.4 mm and 138 had NT ≥ 3.5 mm. Pathogenic copy number variants were found in 1.7%, 6.5% and 13.8% of cases, respectively. CONCLUSION: Our results suggest that CMA should be recommended when fetuses have isolated, mildly increased NT (3.0-3.4 mm). Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

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.

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.

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.

[Implants placement using a novel computerized tactile imaging navigation system].

An implant locating system has been developed. The system contains a stent that maps the jaw bone at the implantation site through the tissue, sends a signal to a computer with a CT scan of the jaw on it, and superimposes the position of the stent on the jaw so that a dental surgeon could angle the implant for placement without requiring to raise a flap to expose the bone. Using a novel tactile technology the system allows safe, accurate, and simple implant placement and design. The ILS software allows: 1. Importing of CT data. 2. Marking a dental arc on the computerized jaw image. 3. Planning of implant location and position on a 3-D view. 4. Affixation of the ILS to the jaw, followed by registration of the stent. 5. Navigated osteotomy and implant placement.

[Image guided dental implantology].

Dental implants insertion is a predictable surgical procedure with very high success rates. An optimal implants placement requires excellent surgical skills and good prosthetic perception. Performing an inaccurate implantation can lead to irreversible surgical damage on the one hand or a prosthetic failure on the other hand. Planning software provide the surgeon with good planning tool; existing navigation systems allow for translating them into performance by semi-active or passive guidance. The later allows for flexibility in the implant location during the operation and real-time tracking of drill position. All of these tools are helpful in avoiding damage to anatomical structures by performing the implantation in close relation to the CT scan. But the solutions that provide most possible advantages requires CT with special markers, long and expansive preoperative preparations and most of all a very high initial cost. These, in addition to a very long learning curve are the reason for these systems not to become a popular working tool. The most important challenges of the next generation systems in dental implants navigation are lower price, smaller size, good performance and reliability and ease of use. This kind of image guided system should allow for preplanning of implants locations, and guided insertion by minimal invasive procedure.

Localization of the gene for Darier disease to a 5-cM interval on chromosome 12q.

Darier disease is an autosomal dominant abnormality of epidermal differentiation characterized clinically by the presence of hyperkeratotic papules on the skin and histologically by the loss of cell cohesion and by disorderly keratinization. Two groups recently found evidence that the gene whose mutations underlie this disease is located at chromosome 12q23-q24.1, a site on chromosome 12 that clearly is distal to the type II keratin gene cluster. We report here evidence for sublocalization to a 5-cM region of that site in an additional ten families of European and Middle Eastern ancestry with a combined lod score in excess of 20.

Short-term recombinant human growth hormone treatment increases growth rate in achondroplasia.

To investigate the effect of recombinant hGH treatment on the growth rate and proportion of individuals with achondroplasia and hypochondroplasia, we studied 15 individuals with these common skeletal dysplasias. The study lasted 24 months and included 6 months of observation, 12 months of hGH therapy (0.04 mg/kg.day), and 6 months of posttreatment growth rate determination. In achondroplasia, the mean growth rate during the hGH treatment (5.3 +/- 1.6 cm) was significantly increased compared with that during the pretreatment (4.0 +/- 1.0 cm.yr, P < 0.01)) and posttreatment periods (3.1 +/- 1.3 cm; P < 0.001). In the 4 children with hypochondroplasia, the growth rate during hGH treatment was 7.0 +/- 2.4 cm/yr and 4.9 +/- 1.5 cm/yr during the pre- and posttreatment periods, respectively. In achondroplasia, there was a significant increase in growth rate of only the lower segment (from 1.1 +/- 1.6 cm/yr to 3 +/- 1.2 cm/yr, P < 0.02). There was no significant acceleration in the growth of the upper segment and of the scanogram measurements of the long bones. No untoward effects were noted. Recombinant hGH increases short-term growth velocity in children with achondroplasia/hypochondroplasia. Unexpectedly, this treatment does not seem to have a lesser effect on limbs than on trunk growth rate and, therefore, during 1 yr of treatment, does not increase body disproportion.

A benign polymorphism in the aspartoacylase gene may cause misinterpretation of Canavan gene testing.

We found normal individuals whose aspartoacylase gene Y231X mutation site consistently gave no signal in a primer extension assay. We determined the nucleotide sequence of the relevant region of the gene in those individuals, and found a new allele with a thymidine residue at the mutation site instead of a cytidine. Since both TAC and TAT code for tyrosine, this sequence polymorphism has no effect on the amino acid sequence of the ASPA protein. We found the relative frequencies of the 693C and the 693T alleles in the tested population to be 0.75 and 0.25 respectively.

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.

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.

Growth, puberty, and endocrine functions in patients with sporadic or familial neurofibromatosis type 1: a longitudinal study.

OBJECTIVE: This study prospectively evaluates parameters of growth, puberty, and attained adult height in children with sporadic or familial occurrence of neurofibromatosis type 1 (NF-1), followed up longitudinally, to define the most important factors affecting these parameters. PATIENTS AND METHODS: The study was made up of 89 patients (55 boys, 34 girls) with sporadic (n = 45) or familial NF-1 (13 affected fathers and 31 affected mothers). The average age at referral was 8.9 years (range 8.5-15 years), and the average follow-up period was 8.5 years (6-15 years). A total of 28 patients attained adult height at the time of the report. Anthropometric measurements and bone age determinations were performed at 6- to 12-month intervals. As indicated, central nervous system (CNS) imaging was performed on 60 patients. Serum levels of thyroid stimulating hormone, free T4, lutheinizing hormone, follicle stimulating hormone, testosterone or estradiol, cortisol, and prolactin were measured in all patients periodically, and the pituitary growth hormone reserve was assessed in 32 short patients. RESULTS: CNS pathology was found in 23 of the 89 patients. A total of 6 patients required neurosurgery, and 2 patients had cranial irradiation. Of these patients, 3 were receiving recombinant growth hormone and thyroxin replacement therapy and 5 patients with precocious puberty were treated with a gonadotropin-releasing hormone analog. All other patients had normal endocrine tests. Precocious puberty was recorded in 5 patients and was more common among the familial cases. The 5 patients with precocious puberty also had CNS pathology. Short stature (<10th percentile) was observed in 25.5% of the patients during the prepubertal period with a significant gradual reduction of their relative height for age (standard scores) during puberty. Short adult height was noted in 12 (43%) of 28 patients, and only 50% of the 28 patients attained an adult height that was appropriate for their respective target height. Short stature was more common among patients with familial NF-1, particularly if the father was affected, and among those patients with CNS pathology. Parental short stature was observed in 39% of the mothers and in 33% of the fathers (59% and 54% among the affected parents, respectively). Tall stature (>90th percentile) was observed in 4 of 89 patients (4.5%), who all had CNS tumors. A highly significant correlation was found among all adult height-predicting parameters (r =.79), and attained adult height was best correlated with the target height (r =.7; n = 28). CONCLUSIONS: Short adult height is an important characteristic of NF-1 and deserves to be emphasized in the evaluation and follow-up of these patients during childhood. Short adult height is strongly linked with familial background of NF-1, in particular if the affected parent is the father, and is affected adversely by the relatively poor pubertal growth. Despite normal pituitary gland and thyroid function tests in most children and adolescents with NF-1, increased incidence of precocious puberty was observed. As the clinical expression in the second generation is more pronounced, the underlying mechanism seems to be mediated by genetic factors that are yet undefined.

Neonatal polycythemia: I. Early diagnosis and incidence relating to time of sampling.

The dynamic changes occurring in hematocrit and blood viscosity within the first 18 hours of life were studied in 50 full-term infants who were vaginally delivered and had weight appropriate for gestational age. In all cases, the cord was clamped within 30 seconds and cord blood was collected from the vein and artery. Subsequently, samples were taken from a peripheral vein at ages 15 minutes, and 2, 4, 6, and between 12 to 18 hours. Both the Hct and blood viscosity reach their peak at age 2 hours. The incidence of neonatal polycythemia varied greatly with age. Thus at the age of 2 hours, ten infants (20%) were polycythemic, whereas by age 6 hours only six (12%) of these infants were still polycythemic and by age 12 to 18 hours only one infant (2%) was polycythemic. A linear correlation was found between cord Hct levels and peripheral venous Hct levels by age 2 hours. None of the infants with cord blood Hct levels less than or equal to 56% had developed polycythemia, whereas ten of the 12 infants with cord Hct levels greater than 56% developed polycythemia. In this particular group of infants, cord blood Hct levels may be used for the screening of neonatal polycythemia.

Neonatal polycythemia: II. Definition related to time of sampling.

The mathematical relationship between blood viscosity and hematocrit levels was studied in 93 venous blood samples drawn within the first 6 hours of life from 20 full-term infants with weight appropriate for gestational age. A highly significant linear correlation (r = .948) between the logarithm of the viscosity at all the shear rates examined and the Hct was found. This indicates an exponential relationship between the blood viscosity and the Hct levels for every value of the Hct greater than 42%. A new dynamic definition of neonatal polycythemia, which takes into consideration the time of sampling, is suggested. By determining the mean + 2 SD, the upper limit of the normal Hct at the age of 2 hours was 71% and at the age of 6 hours was 68%.

Retinopathy of prematurity: incidence and risk factors.

A high incidence of retinopathy of prematurity (ROP) was found in the very low-birth-weight infants discharged from the neonatal intensive care unit during the years 1977 to 1980, in spite of frequent monitoring of oxygen use. Although the yearly incidence of ROP in infants weighing less than 1,500 g varied between 35% to 36%, none were blind. The medical records of 65 infants with a birth weight between 501 and 1,250 g; surviving in 1979 to 1980, were reviewed in order to find risk factors for ROP. There were no significant differences between the 34 infants with ROP and the 31 infants who did not have ROP in mean birth weight or mean gestational age. Of 32 possible risk factors examined, the factors significantly associated with ROP were: apnea with mask and bag ventilation; prolonged parenteral nutrition; number of blood transfusions; and episodes of hypoxemia, hypercarbia, and hypocarbia. A highly significant association between hypocarbia and the development of severe ROP was found.

Trisomy 18 mosaicism in an adult with normal intelligence.

A healthy 30-year-old woman was discovered unexpectedly to have trisomy 18/normal chromosome mosaicism. She was ascertained because of a history of three spontaneous abortions following the birth of a healthy son. Trisomy 18 was present in 18% of her lymphocytes and 2% of her cultured skin fibroblasts. She had several minor malformations associated with trisomy 18 syndrome. She is, to our knowledge, the first person who has clinical stigmata of trisomy 18 but has normal intelligence and leads a normal family life.