Novel mutations in two families with Darier's disease.

BACKGROUND: Darier's disease (DD) is an autosomal dominant skin disorder characterized by abnormal keratinization and acantholysis. Deleterious mutations in the gene ATP2A2 which encodes SERCA2, a calcium pump of the sarco/endoplasmic reticulum underlie the disease. OBJECTIVE: To identify the genetic defect in two Jewish families of eastern-European ancestry with DD. METHODS: DNA was extracted from peripheral blood of six patients and three healthy members of the two families. Polymerase chain reaction (PCR) was carried out to amplify the exons and flanking intron boundaries of the ATP2A2 gene followed by direct sequencing. Restriction fragment analysis verified the presence or absence of the mutations. Results Two novel mutations were identified. A nonsense mutation, a change of C391 to T (R131X) in exon 5, was found in one family and a missense mutation, a change of A530 to C (Q177P) in the second. The mutations were not present in 50 healthy individuals of the same ethnic origin. Both pathogenic mutations are in codons that are located in a highly conserved cytoplasmic beta-strand domain which functions as the transduction site. CONCLUSION: The existence of two mutations in two Jewish families of the same ancestry might confirm the previously published reports that most mutations in that gene are private.

Gender-dependent differences in biological rhythms of mice.

The advantage of a variable's rhythm resides in its optimal time-phasing. This implies that, for a given function, members of a species will strive to exhibit identical time-phasing namely, their inter-individual genetic differences will be masked. To examine the generality of this assumption we explored if inbred mice exhibit gender dependent differences in rhythm parameters of biochemical variables. Male and female mice, entrained by exposure to 12:12 light:dark illumination were sacrificed, every 3 hours over a 27 hours period. Activities of creatine-phosphokinase (CK) and alkaline- phosphatase (AP), white blood cell (WBC) counts and urea nitrogen (UN) concentration were determined at each time point. For each significant rhythm four parameters were computed: period, acrophase, mesor and amplitude. In addition two derived parameters were also calculated: relative-amplitude (RA) and the rate of change in RA (CRA) which provide information about the slope and width of the peak. Patterns of most variables exhibited a compound rhythm containing two significant periodicities. Gender dependent differences were documented in the parameters of most rhythms indicating that the genetic and physiological differences limit to a certain extent the phasing ability of the entraining signals and point to an independent control of each of the rhythm parameters.

Keratin-9 gene mutation in a family with epidermolytic palmoplantar keratoderma.

BACKGROUND: Epidermolytic palmoplantar keratoderma is an autosomal dominant inherited disorder of keratinization. METHODS: We studied five members of a Jewish family with epidermolytic palmoplantar keratoderma. Genomic DNA was extracted from leucocytes, and exon 1 of the keratin 9 gene was amplified using polymerase chain reaction techniques. RESULTS: The mutation was found in exon 1 of the keratin 9 gene in codon 160. CONCLUSIONS: Like most of the other families with clinical features of epidermolytic palmoplantar keratoderma the mutation is found in exon 1 of the keratin 9 gene.

Protein electrophoretic markers in Israel: compilation of data and genetic affinities.

BACKGROUND: A considerable body of data has been accumulated since the 1960s on protein electrophoretic markers in the Jewish populations of Israel. However, in some Jewish communities and for some markers insufficient information has been available. In addition, studies that tried to explore the genetic affinities of various Jewish populations mainly employed antigenic markers and frequently used a small and unrepresentative number of non-Jewish populations as comparisons. AIM: The primary objectives of the present study were to create a comprehensive database for protein electrophoretic markers in Israel and thereby to explore the genetic affinities of different Jewish populations. SUBJECTS AND METHODS: Published information on red cell enzyme and serum protein polymorphisms in Israeli Jewish populations was combined with new data obtained by protein electrophoresis and DNA PCR (polymerase chain reaction) methods to create the database. The genetic affinities were investigated by two methods. Ten Jewish populations were classified in a discriminant analysis based on nine markers and 65 non-Jewish populations. The same markers and populations were also used in a genetic distance analysis. RESULTS: The database contains new information on 15 protein electrophoretic markers in 14 Israeli populations, including three Jewish populations from Turkey, Tunisia and the Caucasus region, for which no or only scarce data were previously available. The discriminant analysis resulted in only two Jewish populations, from Iraq and Yemen, being classified within the Middle Eastern group. According to their genetic distances, no particular genetic similarity was observed between the various Jewish study populations. CONCLUSIONS: In contrast to the conclusions of several previous studies, there was no evidence for close genetic affinities among the Jewish populations or for a Middle Eastern origin for most of them. Since the study is the first to use only the more reliable protein electrophoretic markers, and an appropriately comprehensive panel of non-Jewish populations, the results are regarded as the most reliable available to date.

Screening for fragile X syndrome in women of reproductive age.

We conducted a prospective intervention study of screening for fragile X syndrome in the general population. Antenatal and preconceptional screening were carried out in 9459 women aged between 19 and 44 with no known family history of fragile X syndrome. 80% were tested antenatally. 134 carriers were detected (a frequency of 1 in 70); 130 had a premutation (PM) and 4 had a full mutation (FM). Prenatal diagnosis was carried out in 108 concurrent or subsequent pregnancies among carriers involving 111 fetuses. Nine had an FM, a rate of 1 in 12; two of the affected embryos received the FM directly from the mother and in seven it was the result of expansion from a PM. In all cases with an FM the pregnancy was terminated. In PM carriers there was evidence of a selection against the mutated chromosome with a segregation ratio of 0.40. Owing to the high rate of premutated chromosomes in our population we conclude that screening for fragile X syndrome among women of reproductive age should be more widely available.

A novel mutation in the HEXA gene specific to Tay-Sachs disease carriers of Jewish Iraqi origin.

An increased frequency of carriers of 1:140, as defined by reduced hexosaminidase A (HexA) activity, was observed among Iraqi Jews participating in the Tay-Sachs disease (TSD) carrier detection program. Prior to this finding, TSD among Jews had been restricted to those of Eastern European (Ashkenazi) and Moroccan descent with carrier frequencies of 1:29 and 1:110 for Jews of Ashkenazi and Moroccan extraction, respectively. A general, pan-ethnic frequency of approximately 1:280 has been observed among other Jewish Israeli populations. Analysis of 48 DNA samples from Iraqi Jews suspected, by enzymatic assay, to be carriers revealed a total of five mutations, one of which was novel. In nine carriers (19%), a known mutation typical to either Ashkenazi or Moroccan Jews was identified. DeltaF304/ 305 was detected in four individuals, and + 1278TATC in three. G269S and R170Q each appeared in a single person. The new mutation, G749T, resulting in a substitution of glycine to valine at position 250 has been found in 19 of the DNA samples (40%). This mutation was not detected among 100 non-carrier, Iraqi Jews and 65 Ashkenazi enzymatically determined carriers. Aside from Ashkenazi and Moroccan Jews, a specific mutation in the HEXA gene has now also been identified in Jews of Iraqi descent.

Differences in rhythms of enzymatic activity of maternal and fetal blood.

Blood specimens were obtained at different daily times from the umbilical cord and brachial vein from 53 women within 10 minutes after delivery. Enzyme activities were measured in the white blood cells (WBCs) and serum of each sample. For each enzyme, the results were grouped according to sampling (delivery) times and arrayed to form a 24h time series. Separate time series were generated for maternal and fetal enzymes. Analysis of variance (ANOVA) and cosine best-fit analyses were applied to elucidate significant differences between enzyme activity patterns of mothers and fetuses with regard to time dependency, number of peaks, and acrophases. These and previously documented results indicate that not all mothers and fetuses have rhythms that are concordant. For some enzymes of fetuses, the activity rhythms differ in phase and shape of the time series pattern from those of the mothers; for other enzymes, the activity rhythms develop after birth.

Clinical manifestations of psychiatric patients who are carriers of tay-sachs disease. Possible role of psychotropic drugs.

Patients with late-onset Tay-Sachs disease (TSD) may manifest with neuropsychiatric features. We hypothesized that the prevalence of TSD carriers in psychiatric patients is higher than in the general population and their clinical profile is different from that of their noncarrier counterparts. Among 500 Ashkenazi-Jewish psychiatric patients, 19 were found to be TSD carriers. Their prevalence in the study population is proportional to that in the general Ashkenazi population. However, abnormal neurological findings, especially cognitive impairment, were commoner among TSD carriers (47.4 vs. 26.2%, p = 0.04). It is possible that chronic use of some psychotropic drugs plays a role in this phenomenon.

Deletion patterns of the STS gene and flanking sequences in Israeli X-linked ichthyosis patients and carriers: analysis by polymerase chain reaction and fluorescence in situ hybridization techniques.

BACKGROUND: Deletion of the entire steroid sulfatase (STS) gene is the most common molecular defect in X-linked ichthyosis (XLI) patients. Usually, additional flanking sequences are also missing. The aim of this study was to estimate the extent of deletions in an ethnically heterogeneous population of Israeli XLI patients. METHODS: Multiplex polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques were applied in the analysis of blood samples of 24 patients and amniotic cells of seven affected fetuses from 22 unrelated families. RESULTS: In 19 families, a large deletion of the 2-3 megabase was found. It included the whole STS gene and spanned adjacent areas up- and downstream between the loci DXS 1139 and DXS 1132. Two unrelated families of Iraqi ancestry had a partial deletion of the gene and its centromeric adjacent sequence. In another family, the telomeric end of the extragenic segment was only partially missing. Application of FISH on metaphase blood cells and interphase amniotic cells confirmed the diagnosis of XLI in all patients, except the three with partial intragenic deletion. In those cases, the remaining fraction of the gene was sufficient to provide a false negative result. Diagnosis of carriers and prenatal diagnosis in uncultured cells was applicable only by FISH. CONCLUSIONS: Our study revealed a remarkable heterogeneity in the deletion pattern among Israeli patients with XLI. This heterogeneity could not be attributed to specific ethnic groups because of the small size of the study group. More studies involving patients of various ancestries should be carried out. In addition, this study demonstrated the usefulness of the FISH technique in the prenatal diagnosis of fetuses with suspected XLI.

Heat stable and urea resistant alkaline phosphatase in maternal neutrophils from normal and Down syndrome pregnancies.

Activity levels of total and placental alkaline phosphatase (AP) were determined in maternal serum and neutrophils of normal and Down syndrome pregnancies. The placental iso-enzyme (PAP) was identified by its relative stability to urea and heat. Significant increase in the activity of all iso-enzymes across gestational stages was observed in maternal sera of 28 normal pregnancies. However, in the neutrophil extracts of the same blood samples no differences were detected between trimesters. Another set of experiments was aimed at finding diagnostic differences of PAP activity in maternal neutrophils of normal and trisomy 21 affected pregnancies. No differences of heat stable AP activity were found in maternal samples of 19 normal and 19 Down syndrome affected pregnancies. Urea resistant AP proportions were also similar when measured after 40 minutes of exposure (13 samples in each group). However, a marginally significant increase was observed in the mean value of the Down syndrome affected samples, after 60 minutes of urea treatment. In view of the above results we conclude that neutrophil AP activity is not as yet a useful marker for the screening of trisomy 21 fetuses.

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.

[Comprehensive geriatric assessment--its clinical, social and economic importance and prospects].

It is well known that many elderly patients are referred to nursing homes because of "functional decline" without being thoroughly investigated. We studied 9 elderly patients, all referred to hospital due to functional decline and diagnosed as follows: spinal stenosis--2 cases, depression--3, thyrotoxicosis--1, Parkinson--1, polypharmacy and congestive heart failure--1 patient each. Proper diagnosis and appropriate treatment prevent unnecessary hospitalization in nursing homes. Our study is meant to draw attention to this crucial aspect of geriatric medicine.

Lower frequency of Gaucher disease carriers among Tay-Sachs disease carriers.

The heterozygote frequency of Gaucher disease (GD) and Tay-Sachs disease (TSD) is distinctly high among Ashkenazi Jews (1:29 for TSD and 1:16 for GD). Two main theories have been suggested to explain this high occurrence: a founder effect with subsequent genetic drift, and a selective advantage of heterozygotes. We compared the frequency of the GD most common mutation (1226A-->G) among carriers of the common TSD mutation (+1277 TATC) with the frequency of this mutation in the general Ashkenazi population. The frequency of GD carriers among 308 TSD heterozygotes was 1:28 which is about half the expected (P = 0.03). These results indicate that carriers of both diseases do not possess additional evolutionary advantage over single mutation carriers. A reasonable interpretation of these findings is that one or both mutations have arisen relatively recently in different regions of Europe and have not yet reached genetic equilibrium.

Prevalence of glucocerebrosidase mutations in the Israeli Ashkenazi Jewish population.

Gaucher disease is the most prevalent inherited disease among Ashkenazi Jews. It is very heterogeneous due to a large number of mutations within the glucocerebrosidase gene, whose impaired activity is the cause for this disease. Aiming at determining Gaucher carrier frequency among the Ashkenazi Jewish population in Israel, 1,208 individuals were molecularly diagnosed for six mutations known to occur among Ashkenazi Jewish Gaucher patients, using the newly developed Pronto Gaucher kit. The following mutations were tested: N370S, 84GG, IVS2+1, D409H, L444P, and V394L. Molecular testing of these mutations also allows identification of the recTL allele. The results indicated that Gaucher carrier frequency is 1:17 within the tested population. The prevalence of N370S carriers is 1:17.5. This implies that approximately 1:1225 Ashkenazi Jews will be homozygous for the N370S mutation. Actually, in our study of 1,208 individuals one was found to be homozygous for the N370S mutation. The actual number of known Ashkenazi Jewish Gaucher patients with this genotype is much lower than that expected according to the frequency of the N370S mutation, suggesting a low penetrance of this mutation. Results of loading experiments in cells homozygous for the N370S mutation, as well as cells homozygous for the L444P and the D409H mutations, exemplified this phenomenon.

Time dependency of hematopoietic growth factor coupled to chronotoxicity of carboplatin.

A growing body of data suggests that cancer therapy may be improved and toxicity reduced by administration of antineoplastic agents and cytokines at carefully selected times of the day. The time-dependent effects of each of the drugs have been documented, but not their mutual time dependencies. In the present studies we sought to determine the best time for granulocyte colony-stimulating factor (G-CSF) administration after carboplatin treatment. Carboplatin was injected in different groups of ICR mice at four different circadian stages for 5 consecutive days. Mice were synchronized with an alternation of 12 h of light (from 6:00 a.m. to 6:00 p.m.) and 12 h of darkness. After the last injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Bone marrow toxicity was estimated with the mean 24-h WBC count. The most severe leukopenia occurred in the group injected at 3:00 p.m. - 9 h after light onset. The second set of experiments evaluated the time-dependent effect of G-CSF when singly injected or given after carboplatin injections for 5 days only at 3:00 p.m. G-CSF was injected into various groups on days 8 and 9 at the same four different circadian stages. On the 10th day after the first injection, peripheral WBCs of three mice from each group were counted every 4 h over a 24-h period. Time-dependent effects were observed when G-CSF was injected as a single agent. When G-CSF was given at various times to the group with the most severe carboplatin-induced leukopenia, peripheral WBC count recovery was monitored at all injection times; it reached its highest level (exceeding even that of the control) when G-CSF was injected at 3:00 a.m. Dosing times of both chemotherapy and growth factor are relevant for optimization of carboplatin's hematologic tolerability.

Tay-Sachs disease and HEXA mutations among Moroccan Jews.

Moroccan Jewry (N>750,000) is the only non-Ashkenazi Jewish community in which Tay-Sachs disease (TSD) is not extremely rare. Previous studies among Moroccan Jewish TSD families identified three HEXA mutations. In this study, extended to enzyme-defined and new obilgate TSD carriers, we found four additional mutations. One of them is a novel, IVS5-2(A-->G) substitution, resulting in exon skipping, and it was found only among enzyme-defined carriers. The seven HEXA identified mutations among Moroccan Jews are: deltaF(304/305), R170Q, IVS-2(A-->G), Y180X, E482K, 1278+TATC, and IVS12+1(G-->C). Their respective distribution among 51 unrelated enzyme-defined and obligate carriers is 22:19:6:1:1:1:1. The mutation(s) remain unknown in only three enzyme-defined carriers. Five of the seven Moroccan mutations, including the three most common ones, were not found among Ashkenazi Jews. Compared with the much larger and relatively homogeneous Ashkenazi population, the finding among Moroccan Jews probably reflects their much longer history.

GM2 gangliosidosis B1 variant: biochemical and molecular characterization of hexosaminidase A.

The biochemical properties of hexosaminidase A (HexA) and the coding sequence of the alpha-subunit were examined in a patient of Syrian ancestry with the B1 form of Tay-Sachs disease (TSD). The biochemical characteristics of the variant HexA suggest that both active sites are affected by the mutation(s). Kinetic studies with the beta-subunit specific substrate, 4-methylumbelliferyl-beta-D-N-acetylglucosamine (MUG), revealed a significant difference between the Km values. of normal and variant HexA, while no difference was found when the sulfated substrate MUG-6-sulfate (MUGS), which is specific for the alpha-subunit active site, was used. The Vmax values for both substrates were significantly lower in extracts from B1 variant cells than in control extracts, implying a reduced enzyme level in the variant cells. A noncompetitive inhibitor of the reaction with MUGS, N-acetylglucosamine (NAG), induced a significant inhibition (30%) in the mutant cells only. When MUG was used as substrate, variant HexA was found to be more heat stable (T50 = 170 min) than normal HexA (T50 = 65 min). Furthermore, the mutant cell preparation differed from control in the relation between Hex thermosensitivity and protein concentration in the reaction. Two new mutations were identified in exon 5 of the HexA gene: a C496 to G transversion, which produced an Arg166 -->Gly alteration and a deletion of C498 which generated a shift in the reading frame. The patient was a heterozygote for both mutations even though her parents are first cousins. There is no evidence as yet which of these mutations accounts for the B1 phenotype.

Genetic control of biological rhythms: independent expression of each rhythm parameter.

Biological rhythm whose pattern approaches a sinusoidal curve can be characterized by four parameters: Period, Mesor, Acrophase and Amplitude. Inheritance patterns of these parameters were assessed by monitoring White Blood Cell (WBC) count rhythms of C57BL/6J mice, BALB/c mice and the F1 progeny prior and after injection of Cisplatinum at either 0900, 1500, 2100, or 0300. All untreated mice exhibited similar WBC rhythms while a variety of rhythm phenotypes was revealed among the injected mice. Analyses of the variety in the parental strains and F1 progeny suggested that each of the rhythm parameters is independently controlled.