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BackgroundNeurodevelopmental disorders (NDDs) impact both the development and functioning of the brain and exhibit clinical and genetic variability. RAP and RAB proteins, belonging to the RAS superfamily, are identified as established contributors to NDDs. However, the involvement of SGSM (small G protein signalling modulator), another member of the RAS family, in NDDs has not been previously documented.MethodsProband-only or trio exome sequencing was performed on DNA samples obtained from affected individuals and available family members. The variant prioritisation process focused on identifying rare deleterious variants. International collaboration aided in the identification of additional affected individuals.ResultsWe identified 13 patients from 8 families of Ashkenazi Jewish origin who all carried the same homozygous frameshift variant in SGSM3gene. The variant was predicted to cause a loss of function, potentially leading to impaired protein structure or function. The variant co-segregated with the disease in all available family members. The affected individuals displayed mild global developmental delay and mild to moderate intellectual disability. Additional prevalent phenotypes observed included hypotonia, behavioural challenges and short stature.ConclusionsAn Ashkenazi Jewish homozygous founder variant in SGSM3was discovered in individuals with NDDs and short stature. This finding establishes a connection between another member of the RAS family and NDDs. Additional research is needed to uncover the specific molecular mechanisms by which SGSM3 influences neurodevelopmental processes and the regulation of growth.

BackgroundMonogenic neurodegenerative diseases represent a heterogeneous group of disorders caused by mutations in genes involved in various cellular functions including autophagy, which mediates degradation of cytoplasmic contents by their transport into lysosomes. Abnormal autophagy is associated with hereditary ataxia and spastic paraplegia, amyotrophic lateral sclerosis and frontal dementia, characterised by intracellular accumulation of non-degraded proteins. We investigated the genetic basis of complex HSP in a consanguineous family of Arab-Muslim origin, consistent with autosomal recessive inheritance.MethodsExome sequencing was followed by variant filtering and Sanger sequencing for validation and familial segregation. Studies for mRNA and protein expression used real-time PCR and immunoblots. Patients’ primary fibroblasts were analysed using electron microscopy, immunofluorescence, western blot analysis and ectopic plasmid expression for its impact on autophagy.ResultsWe identified a homozygous missense variant in CHMP3(Chr2:86507484 GRCh38 (NM_016079.4): c.518C>T, p.Thr173Ile), which encodes CHMP3 protein. Segregation analysis validated the presence of the homozygous variant in five affected individuals, while healthy family members were found either heterozygous or wild type for this variant. Primary patient’s fibroblasts showed significantly reduced levels of CHMP3. Electron microscopy disclosed accumulation of endosomes, autophagosomes and autolysosomes in patient’s fibroblasts, which correlated with higher levels of autophagy markers, p62 and LC3-II. Ectopic expression of wild-type CHMP3in primary patient fibroblasts led to reduction of the p62 particles accumulation and number of endosomes and autophagosomes compared with control.ConclusionsReduced level of CHMP3 is associated with complex spastic paraplegia phenotype, through aberrant autophagy mechanisms.

BackgroundCopy number variants (CNVs) associated with late-onset medical conditions are rare but important secondary findings in chromosomal microarray analysis (CMA) performed during pregnancy. Here, we critically review the cases at two tertiary centres to assess the criteria which guide the disclosure of such findings and develop a disclosure decision tool (DDT) aimed at facilitating disclosure decision. Parental decisions on receiving CNVs associated with risks for late-onset conditions were also recorded.MethodsPrenatal CMAs in Hadassah and Shaare Zedek Medical Centers from November 2013 to October 2021 were reviewed for CNVs associated with late-onset conditions. The DDT proposed uses a five-parameter scoring system, which considers the severity, median age of onset, penetrance, understanding of genotype-phenotype correlation and actionability of the finding.ResultsOut of 16 238 prenatal CMAs, 16 (0.1%) harboured CNVs associated with late-onset conditions, 15 of which were disclosed. Outcome information was available on 13 of the 16 pregnancies, all of which continued to delivery.ConclusionsOur suggested DDT will help clinicians to quantitatively weigh the variables associated with CNVs of this type and arrive at a well thought out clinical decision regarding disclosure. Although the prevalence of late-onset conditions as a major finding in the prenatal setup is low, it is expected to rise with the increasing use of non-invasive CMA testing and whole exome and genome sequencing.

The yield of chromosomal microarray analysis (CMA) is well established in structurally normal fetuses (0.4–1.4%). We aimed to determine the incremental yield of exome sequencing (ES) in this population. From February 2017 to April 2022, 1,526 fetuses were subjected to ES; 482 of them were structurally normal (31.6%). Only pathogenic and likely pathogenic (P/LP) variants, per the American College of Medical Genetics and Genomics (ACMG) classification, were reported. Additionally, ACMG secondary findings relevant to childhood were reported. Four fetuses (4/482; 0.8%) had P/LP variants indicating a moderate to severe disease in ATP7B, NR2E3, SPRED1and FGFR3, causing Wilson disease, Enhanced S-cone syndrome, Legius and Muenke syndromes, respectively. Two fetuses had secondary findings, in RETand DSP. Our data suggest that offering only CMA for structurally normal fetuses may provide false reassurance. Prenatal ES mandates restrictive analysis and careful management combined with pre and post-test genetic counseling.

Purpose: Knobloch syndrome is a rare, recessively inherited disorder classically characterized by high myopia, retinal detachment, and occipital encephalocele. Our aim is to report the clinical and genetic findings of four Israeli children affected by Knobloch syndrome.Methods: Retrospective study of four patients diagnosed with Knobloch syndrome, who underwent full ophthalmic examination, electroretinography, and neuroradiologic imaging. Genetic analysis included whole exome sequencing (WES) and Sanger sequencing.Results: The four patients included in this study had high myopia and nystagmus at presentation. Ocular findings included vitreous syneresis, macular atrophy, macular coloboma, and retinal detachment. One child had iris transillumination defects and an albinotic fundus, initially leading to an erroneous clinical diagnosis of albinism. Electroretinography revealed a marked cone-rod pattern of dysfunction in all four children. Brain imaging demonstrated none to severe occipital pathology. Cutaneous scalp changes were present in three patients. WES analysis, confirmed by Sanger sequencing revealed COL18A1biallelic null mutations in all affected individuals, consistent with autosomal recessive inheritance.Conclusions: This report describes variable features in patients with Knobloch syndrome, including marked lack of eye pigment similar to albinism in one child, macular coloboma in two children as well as advanced cone-rod dysfunction in all children. One patient had normal neuroradiologic findings, emphasizing that some affected individuals have isolated ocular disease. Awareness of this syndrome, with its variable phenotype may aid early diagnosis, monitoring for potential complications, and providing appropriate genetic counseling.

PURPOSE: Familial hypercholesterolemia (FH) carries a markedly increased risk for coronary artery disease (CAD). Reduction of plasma low-density lipoprotein cholesterol (LDL-C) levels to the normal range may prevent premature atherosclerosis and usually requires a combination of cholesterol-lowering drugs. The major objective of this study is to compare two different drug combinations for the treatment of heterozygous FH. PATIENTS AND METHODS: The current investigation is a short-term, double-blind study comparing the efficacy and safety of fluvastatin when combined with cholestyramine (group 1) or with bezafibrate (group 2) in 38 patients with heterozygous FH. RESULTS: After 6 weeks of combination treatment, in comparison to a drug-free baseline (patients receiving single-blind placebo during the lead-in period of an earlier study, ie, before ever receiving fluvastatin), the combination of 40 mg/d of fluvastatin with 400 mg/d of bezafibrate in group 2 reduced plasma LDL-C levels by 35% as compared with 32% in group 1, and reduced the LDL-C/high-density cholesterol (HDL-C) ratio by 46%, compared to 37% in group 1 (a nonsignificant difference for both comparisons). When compared to an intermittent 6-week open-label administration of 40 mg fluvastatin monotherapy, the addition of cholestyramine or bezafibrate each reduced LDL-C by an additional 13% (P

Consanguinity, commonplace in many regions around the globe, is associated with an increased risk of autosomal recessive (AR) genetic disorders. Consequently, consanguineous couples undergoing preimplantation genetic diagnosis (PGD) for one Mendelian disorder may be at increased risk for a child with a second, unrelated AR genetic disorder. We examined the yield of exome analysis for carrier screening of additional AR disorders, beyond the primary diagnosis, amongst consanguineous vs. non-consanguineous populations. Parental samples from trio exomes of 102 consanguineous families and 105 non-consanguineous controls were evaluated for shared carrier status, after disregarding the primary molecular diagnosis. Results were sub-classified according to disease severity. Secondary shared carrier status for pathogenic and likely pathogenic variants leading to AR disorders of moderate to profound severity was identified in 10/102 (9.8%) consanguineous couples, as compared to 1/105 (0.95%) non-consanguineous couples (χ2= 8.0565, pvalue < 0.005). Higher inbreeding coefficient values, calculated from individual exomes, correlated with secondary shared carrier status for diseases of moderate to profound severity (r= 0.17, pvalue < 0.0125). Our results indicate that consanguineous couples undergoing PGD are at increased risk for a second genetic disease of moderate to profound severity. This study represents an underestimate of the rate of secondary shared carrier status due to inability to detect deep intronic variants, no assessment of copy number variants, and false negative results stemming from stringent variant interpretation. False positive results may result from inaccuracies in public databases. Additional studies in consanguineous populations will determine whether exome-based carrier screening should be recommended to all couples undergoing PGD.

BackgroundUbiquitination has a central role in numerous biological processes, including cell development, stress responses and ageing. Perturbed ubiquitination has been implicated in human diseases ranging from cancer to neurodegenerative diseases. SIAH1encodes a RING-type E3 ubiquitin ligase involved in protein ubiquitination. Among numerous other roles, SIAH1 regulates metabotropic glutamate receptor signalling and affects neural cell fate. Moreover, SIAH1 positively regulates Wnt signalling through ubiquitin-mediated degradation of Axin and accumulation of β-catenin.MethodsTrio exome sequencing followed by Sanger validation was undertaken in five individuals with syndromic developmental delay. Three-dimensional structural modelling was used to predict pathogenicity of affected residues. Wnt stimulatory activity was measured by luciferase reporter assays and Axin degradation assays in HEK293 cells transfected with wild-type and mutant SIAH1 expression plasmids.ResultsWe report five unrelated individuals with shared features of developmental delay, infantile hypotonia, dysmorphic features and laryngomalacia, in whom exome sequencing identified de novo monoallelic variants in SIAH1. In silico protein modelling suggested alteration of conserved functional sites. In vitro experiments demonstrated loss of Wnt stimulatory activity with the SIAH1 mutants, suggesting variant pathogenicity.ConclusionOur results lend support to SIAH1as a candidate Mendelian disease gene for a recognisable syndrome, further strengthening the connection between SIAH1and neurodevelopmental disorders. Furthermore, the results suggest that dysregulation of the Wnt/β-catenin pathway may be involved in the pathogenesis.

Rab proteins coordinate inter-organellar vesicle-mediated transport, facilitating intracellular communication, protein recycling, and signaling processes. Dysfunction of Rab proteins or their direct interactors leads to a wide range of diseases with diverse manifestations. We describe seven individuals from four consanguineous Arab Muslim families with an infantile-lethal syndrome, including failure to thrive (FTT), chronic diarrhea, neonatal respiratory distress, variable pituitary dysfunction, and distal arthrogryposis. Exome sequencing analysis in the independent families, followed by an internal gene-matching process using a local exome database, identified a homozygous splice-site variant in MADD(c.2816 + 1 G > A) on a common haplotype. The variant segregated with the disease in all available family members. Determination of cDNA sequence verified single exon skipping, resulting in an out-of-frame deletion. MADDencodes a Rab guanine nucleotide exchange factor (GEF), which activates RAB3 and RAB27A/27B and is thus a crucial regulator of neuromuscular junctions and endocrine secretory granule release. Moreover, MADD protects cells from caspase-mediated TNF-α-induced apoptosis. The combined roles of MADD and its downstream effectors correlate with the phenotypic spectrum of disease, and call for additional studies to confirm the pathogenic mechanism and to investigate possible therapeutic avenues through modulation of TNF-α signaling.

The founder variant DHCR7:c.964-1G>C causing autosomal recessive Smith–Lemli–Opitz (SLOS) was introduced into the Israeli preconception carrier program for Ashkenazi Jews in 2017 because of the high carrier frequency in this population (2.3%). Other disease-causing variants in DHCR7 are relatively rare in Israeli population. Discrepancy between the carrier frequency and disease prevalence raises the question of the actual risks for affected offspring for couples detected by the screening program. We performed a literature review of all relevant publications regarding homozygous DHCR7:c.964-1G>C fetuses/patients. We also collected clinical data about couples identified in the national screening program, including reproductive history. Out of 32 homozygous fetuses, six died in utero, 11 pregnancies were terminated during second trimester, and 15 children were born. All died between first days of life till 3 months of age. Reproductive history of SLOS-at-risk couples showed that after correction for ascertainment bias, out of 61 pregnancies, there was an absence of affected fetuses/children and an excess of miscarriages even if assumed that all the homozygous fetuses were miscarried. Out of these, eight families were Israelis, they had a total of one sick child, 21 healthy children, and 21 miscarriages. Our observations support the previous knowledge that homozygosity for c.964-1G>C in DHCR7leads to a severe phenotype or early miscarriage. An unexpected observation was the excess of early miscarriages. This phenomenon is unclear and awaits further studies.

The transforming growth factor-beta (TGFβ) signaling pathway is essential for palatogenesis and retinal development. Glycoprotein A repetitions predominant (GARP), encoded by LRRC32, is a TGFβ cell surface receptor that has been studied primarily in the context of cellular immunity. We identified a homozygous stop-gain variant in LRRC32(c.1630C>T; p.(Arg544Ter)) in two families with developmental delay, cleft palate, and proliferative retinopathy. Garp-null mice have palate defects and die within 24 h after birth. Our study establishes LRRC32as a candidate disease-associated gene in humans and lends further support to the role of the TGFβ pathway in palatogenesis and retinal development.

Patients with familial hyperparathyroidism and low urinary calcium excretion may have familial hypocalciuric hypercalcemia (FHH) with mutations in one of three genes: the calcium-sensing receptor (CaSR) defining FHH-type 1, the adaptor-related protein complex 2 (AP2S1) related to FHH-type 3 or the G-protein subunit alpha11 (GNA11) associated with FHH-type 2. We aimed to evaluate the presence of mutations in these genes and to identify phenotypic specificities and differences in these patients. Selected patients were recruited for genetic evaluation. After informed consent was signed, blood for DNA extraction was obtained and genetic sequencing of CaSRwas done. In negative cases, we further performed sequencing of AP2S1and GNA11. A total of 10 index cases were recruited. CaSRsequencing yielded three missense heterozygous mutations (30%): c.554G > A (p.I32V) previously characterized by our team, c.1394 G > A (p.R465Q) and a novel expected disease-causing mutation c.2479 A > C (p.S827R). We identified 2 additional patients (20%) carrying the deleterious recurrent mutation c.44G > T (p.R15L) in the AP2S1gene. No GNA11mutation was found. Clinically, patients with AP2S1mutations had significant cognitive and behavioral disorders, and higher blood calcium and magnesium levels than patients with FHH1. CaSRand AP2S1sequencing is worthwhile in patients with familial hyperparathyroidism and phenotype suggesting FHH as it can diagnose up to 50% of cases. GNA11mutations seem much rarer. Learning disabilities in these patients, associated with higher serum calcium and magnesium levels may suggest the presence of AP2S1rather than CaSRmutation and may guide the first step in the genetic evaluation.

A 30-year-old man with sensorineural hearing loss presented with subacute somnolence, slurred speech, and unsteady gait following treatment with peginterferon α-2b and ribavirin for chronic hepatitis C virus. Examination revealed scanning speech, horizontal nystagmus, gait ataxia, and symmetric hyporeflexia with distal sensory loss. There was no palatal myoclonus. Metabolic and serologic workup and blood lactate were unrevealing. Brain MRI demonstrated bilateral hypertrophic olivary degeneration (HOD, figure). Whole exome sequencing identified a homozygous pathogenic p.W748S POLGmutation.1Differential diagnosis of bilateral HOD includes mutations in the nuclear genes crucial to mitochondrial function, POLGand SURF1.2

IMPORTANCE: We describe a deep intronic mutation in adult polyglucosan body disease. Similar mechanisms can also explain manifesting heterozygous cases in other inborn metabolic diseases. OBJECTIVE: To explain the genetic change consistently associated with manifesting heterozygous patients with adult polyglucosan body disease. DESIGN, SETTING, AND PARTICIPANTS: This retrospective study took place from November 8, 2012, to November 7, 2014. We studied 35 typical patients with adult polyglucosan body disease, of whom 16 were heterozygous for the well-known c.986A>C mutation in the glycogen branching enzyme gene (GBE1) but harbored no other known mutation in 16 exons. MAIN OUTCOMES AND MEASURES: All 16 manifesting heterozygous patients had lower glycogen branching activity compared with homozygous patients, which showed inactivation of the apparently normal allele. We studied the messenger ribonucleic acid (mRNA) structure and the genetic change due to the elusive second mutation. RESULTS: When we reverse transcribed and sequenced the mRNA of GBE1, we found that all manifesting heterozygous patients had the c.986A>C mutant mRNA and complete lack of mRNA encoded by the second allele. We identified a deep intronic mutation in this allele, GBE1-IVS15 + 5289_5297delGTGTGGTGGinsTGTTTTTTACATGACAGGT, which acts as a gene trap, creating an ectopic last exon. The mRNA transcript from this allele missed the exon 16 and 3′UTR and encoded abnormal GBE causing further decrease of enzyme activity from 18% to 8%. CONCLUSIONS AND RELEVANCE: We identified the deep intronic mutation, which acts as a gene trap. This second-most common adult polyglucosan body disease mutation explains another founder effect in all Ashkenazi-Jewish cases.

The calcium-sensing receptor (CaSR) is a G-protein-coupled receptor with a crucial role in calcium homeostasis. Mutations in the CaSRgene may lead to specific parathyroid disorders due to either gain-of-function (autosomal dominant hypercalciuric hypocalcemia; ADHH) or loss-of-function (familial hypocalciuric hypercalcemia; FHH). Our aim was to evaluate CaSRmutations as a cause of disease in selected patients. We identified and recruited patients with phenotypes suggestive of CaSR-related parathyroid disorders. DNA was extracted, and CaSRgene was sequenced. Live-ratiometric measurements of intracellular [Ca2+] and Western blot assays for evaluation of MAPK phosphorylation in response to changes in extracellular [Ca2+] were performed in transiently transfected HEK-293T cells to functionally characterize mutants. A total of 21 patients were evaluated, seven of them with idiopathic hypoparathyroidism (suspected ADHH) and 14 with hyperparathyroidism (suspected FHH). In the latter group two patients were found to harbor missense mutations: a novel heterozygous I32 V mutation in a female index case and a sporadic known R185Q mutation in a 1-year-old girl. In-vitro functional studies showed that I32 V is an inactivating mutation. In our study, most patients had normal CaSRsequencing. This suggests that phenotypic pitfalls may occur at time of patients’ selection for CaSRsequencing. In one patient with strong positive pre-test probability based on both familial history and appropriate phenotype, a novel I32 V mutation leading to FHH was identified and characterized. In cases of familial parathyroid disorders, CaSRsequencing should be performed, but if negative, one should consider involvement of alternative genes or mechanisms.

To present the clinical, molecular, and cell biological findings in a family with an autosomal recessive form of hereditary spastic paraplegia characterized by a combination of spastic paraplegia, optic atrophy, and peripheral neuropathy (SPOAN).

IMPORTANCE: Hereditary spastic paraplegia is a highly heterogeneous group of neurogenetic disorders with pure and complicated clinical phenotypes. No treatment is available for these disorders. We identified 2 unrelated families, each with 2 siblings with severe methylenetetrahydrofolate reductase (MTHFR) deficiency manifesting a complicated form of adult-onset hereditary spastic paraparesis partially responsive to betaine therapy. OBSERVATIONS: Both pairs of siblings presented with a similar combination of progressive spastic paraparesis and polyneuropathy, variably associated with behavioral changes, cognitive impairment, psychosis, seizures, and leukoencephalopathy, beginning between the ages of 29 and 50 years. By the time of diagnosis a decade later, 3 patients were ambulatory and 1 was bedridden. Investigations have revealed severe hyperhomocysteinemia and hypomethioninemia, reduced fibroblast MTHFR enzymatic activity (18%-52% of control participants), and 3 novel pathogenic MTHFR mutations, 2 as compound heterozygotes in one family and 1 as a homozygous mutation in the other family. Treatment with betaine produced a rapid decline of homocysteine by 50% to 70% in all 4 patients and, over 9 to 15 years, improved the conditions of the 3 ambulatory patients. CONCLUSIONS AND RELEVANCE: Although severe MTHFR deficiency is a rare cause of complicated spastic paraparesis in adults, it should be considered in select patients because of the potential therapeutic benefit of betaine supplementation.

The two oxysterols, 27-hydroxycholesterol (27OH) and 24S-hydroxycholesterol (24OH), are both inhibitors of cholesterol synthesis and activators of the liver X receptor (LXR) in vitro. Their role as physiological regulators under in vivo conditions is controversial, however. In the present work, we utilized a previously described mouse model with overexpressed human sterol 27-hydroxylase (CYP27A1). The levels of 27OH were increased about 12-fold in the brain. The brain levels of HMG-CoA reductase mRNA and HMG-CoA synthase mRNA levels were increased. In accordance with increased cholesterol synthesis, most of the cholesterol precursors were also increased. The level of 24OH, the dominating oxysterol in the brain, was decreased by about 25%, most probably due to increased metabolism by CYP27A1. The LXR target genes were unaffected or slightly changed in a direction opposite to that expected for LXR activation. In the brain of Cyp27−/−mice, cholesterol synthesis was slightly increased, with increased levels of cholesterol precursors but normal mRNA levels of HMG-CoA reductase and HMG-CoA synthase. The mRNA levels corresponding to LXR target genes were not affected. The results are consistent with the possibility that both 24OH and 27OH are physiological suppressors of cholesterol synthesis in the brain. The results do not support the contention that 27OH is a general activator of LXR target genes in this organ.

The rare disease cerebrotendinous xanthomatosis (CTX) is due to a lack of sterol 27-hydroxylase (CYP27A1) and is characterized by cholestanol-containing xanthomas in brain and tendons. Mice with the same defect do not develop xanthomas. The driving force in the development of the xanthomas is likely to be conversion of a bile acid precursor into cholestanol. The mechanism behind the xanthomas in the brain has not been clarified. We demonstrate here that female cyp27a1−/−mice have an increase of cholestanol of about 2.5- fold in plasma, 6-fold in tendons, and 12-fold in brain. Treatment of cyp27a1−/−mice with 0.05% cholic acid normalized the cholestanol levels in tendons and plasma and reduced the content in the brain. The above changes occurred in parallel with changes in plasma levels of 7α-hydroxy-4-cholesten-3-one, a precursor both to bile acids and cholestanol. Injection of a cyp27a1−/−mouse with 2H7-labeled 7α-hydroxy-4-cholesten-3-one resulted in a significant incorporation of 2H7-cholestanol in the brain. The results are consistent with a concentration-dependent flux of 7α-hydroxy-4-cholesten-3-one across the blood-brain barrier in cyp27a1−/−mice and subsequent formation of cholestanol. It is suggested that the same mechanism is responsible for accumulation of cholestanol in the brain of patients with CTX.

Antenatal presentation of carnitine palmitoyltransferase type II deficiency due to mutations in the CPT2gene has been rarely reported. We report an Ashkenazi Jewish family with 3 terminated pregnancies for multicystic kidneys and/or hydrocephalus. Fetal autopsy after termination of the couple's 4th pregnancy (sib 2) showed renal parenchyma replaced by cysts that appeared to increase in diameter toward the medulla. Fetopsy after termination of the 7th pregnancy (sib 3) revealed micrognathia; hypospadias; cystic renal dysplasia; hepatosteatosis; and lipid accumulation in the renal tubular epithelium, myocardium, and skeletal muscle. Microvascular proliferative changes and focal polymicrogyria were seen in the brain. A beta-oxidative enzyme deficiency was suspected. CPT2gene analysis showed a homozygous complex haplotype for the F448L mutation associated with a c.del1238_1239AG (p.Q413fs) truncating mutation in exon 4. Carnitine palmitoyltransferase type II deficiency should be included in the differential diagnosis in fetuses of Ashkenazi origin with multicystic kidneys and unusual cerebral findings.

Niemann–Pick type C NPC disease is a lysosomal neurovisceral storage disease. The spectrum of the clinical presentation as well as the severity of the disease and the age of presentation may be highly variable. Fetal presentation is rarely described in the literature. Here, we report on seven new cases of fetal onset NPC of whom two were diagnosed in utero and five postnatally. The fetal clinical presentation, included, in utero splenomegaly 67, in utero hepatomegaly 57, in utero ascites 47, intra uterine growth retardation IUGR 27, and oligohydramnios 27. Placentomegaly was present in two of the three pregnancies examined. Congenital thrombocytopenia 44, congenital anemia 24, and petechial rash 25 were diagnosed immediately after birth. Three patients were born preterm. Pregnancy and postnatal outcome were remarkably poor with one case of intrauterine fetal death, one elective termination of pregnancy, and four patients who died within the first months of life from a rapidly fatal neonatal cholestatic disease. NPC1gene mutation analysis identified all of the mutant alleles including three novel mutations. Splenomegaly, hepatomegaly, and ascites were the most consistent prenatal ultrasonographic findings of the NPC fetuses. We suggest that once identified these findings, should raise the suspicion of fetal NPC. Our study further expands the antenatal clinical spectrum of NPC and provides clues to its prenatal diagnosis. © 2009 WileyLiss, Inc.

BACKGROUND Hereditary spastic paraplegia (HSP) with thin corpus callosum (TCC) is an autosomal recessive form of complicated HSP mainly characterized by slowly progressive spastic paraparesis and mental deterioration beginning in the second decade of life. The locus for HSP-TCC, designated SPG11, was mapped to chromosome 15q13-15 in some of the affected families from Japan, Europe, and North America, spanning an interval of 17.5 megabases (Mb). OBJECTIVE To perform a clinical and genetic study of HSP-TCC. DESIGN AND SETTING Case series; multi-institutional study. PATIENTS Seven patients with HSP-TCC who belong to 3 consanguineous families of Arab origin residing in Israel. RESULTS The 7 patients manifested a relatively similar combination of adolescence-onset cognitive decline and spastic paraparesis with TCC on brain magnetic resonance imaging. After excluding the SPG7 locus, we tested the 3 families for linkage to the SPG11, SPG21/MAST, and ACCPN loci associated with autosomal recessive disorders with TCC. Two families showed evidence for linkage to SPG11 (Zmax = 5.55) and reduced the candidate region to 13 Mb. CONCLUSIONS Our findings in HSP-TCC further confirm its worldwide distribution and genetic heterogeneity, and they significantly reduce the candidate SPG11 interval.Arch Neurol. 2006;63:756-760 --

CYP27-overexpressed transgenic mice were generated with the use of a human full-length CYP27coding region cloned into a ubiquitous expression vector. Positive transgenic mice were identified by tail DNA genotyping and high fecal 27-hydroxycholesterol content. The levels of 27-hydroxycholesterol were found to be 3–5 times higher in the circulation and the tissues of the overexpressed mice when compared with littermate controls. There were no gross morphological differences between the overexpressed mice and their controls. Total cholesterol and triglyceride levels were not affected by overexpression of CYP27. Serum lathosterol was also normal, suggesting a normal rate of cholesterol synthesis. Serum levels of 7α-hydroxycholesterol were unaffected, suggesting a normal rate of bile acid formation in the pathway involving cholesterol 7α-hydroxylase. Biliary bile acid composition was slightly affected by CYP27overexpression in female but not in male mice. Fecal levels of neutral steroids were slightly but significantly increased in overexpressor female mice but not in male mice. Levels of 24-hydroxycholesterol in the circulation were significantly reduced in the overexpressed mice, probably as a consequence of a recently described catabolic pathway involving CYP27. Combined with the results of our previous work on mice with a disruption of the CYP27gene, the present results suggest that the levels of 27-hydroxycholesterol are not of critical importance for cholesterol homeostasis in mice.

Purpose: Niemann-Pick disease type C (NP-C) is an autosomal recessive lipid storage disease manifested by an impairment in cellular cholesterol homeostasis. The clinical phenotype of NP-C is extremely variable, ranging from an acute neonatal form to an adult late-onset presentation. To facilitate phenotype-genotype studies, we have analyzed multiple Israeli NP-C families.Methods: The severity of the disease was assessed by the age at onset, hepatic involvement, neurological deterioration, and cholesterol esterification studies. Screening of the entire NPC1 coding sequence allowed for molecular characterization and identification of disease causing mutations.Results: A total of nine NP-C index cases with mainly neurovisceral involvement were characterized. We demonstrated a possible link between the severity of the clinical phenotype and the cholesterol esterification levels in fibroblast cultures following 24 hours of in vitro cholesterol loading. In addition, we identified eight novel mutations in the NPC1 gene.Conclusions: Our results further support the clinical and allelic heterogeneity of NP-C and point to possible association between the clinical and the biochemical phenotype in distinct affected Israeli families.

Sex chromosome aneuploidy (SCA), when detected in amniocentesis, is usually an unexpected result of a test carried out for another purpose. For most SCAs, the prognosis is milder and less predictable than trisomy 21, and therefore parents are faced with a difficult decision regarding the option of pregnancy termination. While studies from Europe and the USA report a declining trend in termination rates for SCA, our local experience is different. During the period 1989–1998, we diagnosed 60 SCA (including mosaics) in 20 106 amniocenteses (0.29%) and 48 (80%) of these pregnancies were terminated, a significantly higher proportion than has been reported in Europe and the USA. The present study shows that the difference between our experience and others' may be related to differences in cultural norms and values. Thirty women were interviewed, of whom 23 terminated and seven continued the pregnancy. Interview analyses showed that the main reason behind the decision to terminate the pregnancy was associated with the parents' fear of non‐specific abnormality of the child, and concerns about abnormal sexual development. Although genetic counseling practised in our center aims to be non‐directive, 56% of the women reported that the counseling was either directive towards termination, or that they at least felt that the counselor's attitude was pro‐termination. Most women (93%) reported themselves as having come to terms with their decision. Copyright © 2001 John Wiley & Sons, Ltd.

Cerebrotendinous xanthomatosis is an autosomal recessive lipid-storage disease caused by mutations in the sterol 27-hydroxylase (CYP27) gene. Recent cloning and characterization of CYP27 enables further analysis and understanding of the pathophysiology of this multisystem disease. Molecular diagnosis provides means for the identification of heterozygotes and pre-symptomatic detection of affected individuals.

ald, a recessive allele in AKR inbred mice, is responsible for complete adrenocortical lipid depletion in postpubertal males, which appears to be androgen dependent. Two recent observations (adrenocortical lipid depletion in acyl-CoA:cholesterol acyltransferase-deficient (Acact−/−) mice and the mapping of Acactto a region of chromosome 1 containing thealdlocus) prompted us to ask whether adrenocortical lipid depletion in AKR mice results from an Acactmutation. Refined genetic mapping of Acactand aldwas consistent with colocalization of these loci. CrossingAcact−/− with AKR (ald/ald) mice yielded postpubertal male offspring characterized by adrenocortical lipid depletion, indicating that these loci are not complementational and are therefore allelic. Immunoblotting of preputial gland homogenates demonstrated that AKR mice had an ACAT protein with a lower molecular mass than other mouse strains. Analysis of AcactcDNA from AKR mice revealed a deletion of the first coding exon and two missense mutations. Despite these coding sequence differences, the ACAT protein from the aldallele catalyzed cholesterol esterification activity at levels similar to that of wild-type protein. We speculate that the adrenocortical lipid depletion resulting from thealdmutation is caused by an altered susceptibility of the mutant protein to modifying factors, such as androgen production at puberty, in an as yet undetermined manner.

Macrophages in atherosclerotic lesions accumulate large amounts of cholesteryl-fatty acyl esters (“foam cell” formation) through the intracellular esterification of cholesterol by acyl-coenzyme A:cholesterolO-acyltransferase (ACAT). In this study, we sought to determine the subcellular localization of ACAT in macrophages. Using mouse peritoneal macrophages and immunofluorescence microscopy, we found that a major portion of ACAT was in a dense reticular cytoplasmic network and in the nuclear membrane that colocalized with the luminal endoplasmic reticulum marker protein-disulfide isomerase (PDI) and that was in a similar distribution as the membrane-bound endoplasmic reticulum marker ribophorin. Remarkably, another portion of the macrophage ACAT pattern did not overlap with PDI or ribophorin, but was found in as yet unidentified cytoplasmic structures that were juxtaposed to the nucleus. Compartments containing labeled β-very low density lipoprotein, an atherogenic lipoprotein, did not overlap with the ACAT label, but rather were embedded in the dense reticular network of ACAT. Furthermore, cell-surface biotinylation experiments revealed that freshly harvested, non-attached macrophages, but not those attached to tissue culture dishes, contained ∼10–15% of ACAT on the cell surface. In summary, ACAT was found in several sites in macrophages: a cytoplasmic reticular/nuclear membrane site that overlaps with PDI and ribophorin and has the characteristics of the endoplasmic reticulum, a perinuclear cytoplasmic site that does not overlap with PDI or ribophorin and may be another cytoplasmic structure or possibly a unique subcompartment of the endoplasmic reticulum, and a cell-surface site in non-attached macrophages. Understanding possible physiological differences of ACAT in these locations may reveal an important component of ACAT regulation and macrophage foam cell formation.

Adult polyglucosan body disease (APBD) is a late‐onset, slowly progressive disorder of the nervous system caused by glycogen branching enzyme (GBE) deficiency in a subgroup of patients of Ashkenazi Jewish origin. Similar biochemical finding is shared by glycogen storage disease type IV (GSD IV) that, in contrast to APBD, is an early childhood disorder with primarily systemic manifestations. Recently, the GBE cDNA was cloned and several mutations were characterized in different clinical forms of GSD IV. To examine whether mutatins in the GBE gene account for APBD, we studied 7 patients from five Jewish families of Ashkenazi ancestry. The diagnosis was based on the typical clinical and pathological findings, and supported by reduced GBE activity. We found that the clinical and biochemical APBD phenotype in all five families cosegregated with the Tyr329Ser mutation, not detected in 140 controls. As this mutation was previously identified in a nonprogressive form of GSD IV and was shown in expression studies to result in a significant residual GBE activity, present findings explain the late onset and slowly progressive course of APBD in our patients. We conclude that APBD represents an allelic variant of GSD IV, but the reason for the difference in primary tissue involvement must be established.

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the low density lipoprotein (LDL) receptor gene. Here, we characterize an LDL receptor mutation that is associated with a distinct haplotype and that causes FH in the Jewish Sephardic population originating from Safed, a town in northern Israel. The mutation was found in eight FH families originating from this community comprising 10% of heterozygote FH index cases screened in Israel. The mutation was not found in four additional FH heterozygotes whose hypercholesterolemia co-segregated with an identical LDL receptor gene haplotype. A guanine to cytosine substitution results in a missense mutation (asp147 to his) in the fourth repeat of the binding domain encoded by exon 4 of the LDL receptor gene. The mutant receptor protein was synthesized in cultured cells as a 120kDa precursor form that failed to undergo normal processing to a mature cell surface form. Most of the receptor precursors were degraded in the endoplasmic reticulum. The small number of mutant receptors on the cell surface were unable to bind LDL or ß very low density lipoprotein. The abnormal behavior of the mutant receptor was reproduced by site-directed mutagenesis and expression of the mutant protein in CHO cells. The mutation can be diagnosed by allele-specific oligonucleotide hybridization of polymerase chain reaction amplified DNA from FH patients.

We report three members of a single family with an apparently autosomal dominant, nonparoxysmal, hyperkinetic movement disorder with onset in adolescence. The proband, a 56-year-old woman, manifested dystonia, tremor and myoclonus; one of her daughters exhibited myoclonus with tremor, and the other demonstrated myoclonus with chorea later accompanied by tremor and dystonia. The slowly progressive but not debilitating symptoms were restricted to the head, arms and hands and were only moderately affected by alcohol. Laboratory investigations failed to identify any abnormality, and linkage analysis excluded the region containing the DYT1 locus, indicating that the gene responsible for idiopathic torsion dystonia was not implicated in this family. While this disorder shares manifestations with myoclonic dystonia, essential myoclonus and benign chorea, the marked intrafamilial heterogeneity and the sex-limited phenotype expressed only in females of two generations appear to be unique.

In Wolfram syndrome insulin-dependent diabetes is associated with a multisystem neurodegenerative disorder. There are no prior reports of kidney transplantation in patients with Wolfram syndrome.

Here, we report the prenatal diagnosis of familial hypercholesterolemia in a Christian-Arab family that carries the “Lebanese” mutation, a single base substitution that creates a HinfI restriction site, at the low density lipoprotein (LDL) receptor locus. Polymerase chain reaction amplification and restriction analysis were performed on genomic DNA extracted from a chorionic villus sample. In conjunction with karyotype analysis, the fetus was identified as a heterozygous female. Analysis of LDL receptor restriction fragment length polymorphisms confirmed the presence of a male parent marker and revealed that the fetus inherited the mutant gene from its mother. This technique offers a simple and rapid diagnostic tool that can be carried out at an early stage of gestation. It is recommended for families and population groups with molecularly defined LDL receptor mutations.

A 30-year-old man with sensorineural hearing loss presented with subacute somnolence, slurred speech, and unsteady gait following treatment with peginterferon α-2b and ribavirin for chronic hepatitis C virus. Examination revealed scanning speech, horizontal nystagmus, gait ataxia, and symmetric hyporeflexia with distal sensory loss. There was no palatal myoclonus. Metabolic and serologic workup and blood lactate were unrevealing. Brain MRI demonstrated bilateral hypertrophic olivary degeneration (HOD, figure). Whole exome sequencing identified a homozygous pathogenic p.W748S POLGmutation.1Differential diagnosis of bilateral HOD includes mutations in the nuclear genes crucial to mitochondrial function, POLGand SURF1.2