Recombinant long-acting glycoPEGylated factor IX (nonacog beta pegol) in haemophilia B: assessment of target joints in multinational phase 3 clinical trials

BACKGROUND

The paradigm(™) 2 and 4 phase 3 clinical trials investigated the safety and efficacy of nonacog beta pegol, a recombinant glycoPEGylated factor IX (FIX) with extended half-life, in previously treated haemophilia B patients.

AIM

These post hoc analyses investigated the bleeding patterns in target joints.

METHODS

Patients randomized to 40 or 10 IU kg(-1) once weekly prophylaxis who had at least one target joint were included. Baseline demographics and disease-specific data were collected. Bleeding patterns were assessed, and an International Society on Thrombosis and Haemostasis (ISTH) definition of target joints was used.

RESULTS

A total of 67% and 8% of patients in the 40 and 10 IU kg(-1) arm, respectively, did not experience target joint bleeds during the paradigm(™) 2 trial. Twenty-four target joints were recorded in each prophylaxis arm at baseline. During the paradigm(™) 2 trial, no bleeds were reported in 17 (71%) and 7 (29%) target joints in the 40 and 10 IU kg(-1) arms respectively. All target joint bleeds in the 40 IU kg(-1) once weekly prophylaxis arm were controlled with a single injection of 40 IU kg(-1) nonacog beta pegol. By the latest ISTH definition, 90% and 58% of target joints in the 40 and 10 IU kg(-1) arms, respectively, were no longer considered target joints at the end of the paradigm(™) 2 trial. At the end of the paradigm(™) 4 extension trial, all target joints in the 40 IU kg(-1) arm were no longer considered target joints.

CONCLUSION

Routine prophylaxis with 40 IU kg(-1) once weekly nonacog beta pegol has the potential for effective management of target joint bleeds in haemophilia B patients.

Limitations of sniff nasal pressure as an outcome measurement in amyotrophic lateral sclerosis patients in a clinical trial

BACKGROUND

The forced vital capacity (FVC) is an established measure in amyotrophic lateral sclerosis (ALS) clinical trials. Recently the sniff nasal inspiratory pressure (SNIP) test has been increasingly used as a respiratory measure.

OBJECTIVES

It was the aim of this study to assess the feasibility of SNIP as an outcome measure in a phase III clinical trial with a lead-in design.

METHODS

Twenty patients were enrolled in a randomized clinical trial. FVC, SNIP in sitting (SNIPsitt) and supine (SNIPsup) positions, and the ALS functional rating scale score (ALSFRS-R) were measured every 4 weeks.

RESULTS

Complete data were available for 19 patients over 5 months. Baseline values were normal for FVC (101 ± 14%) but abnormal for SNIPsitt and SNIPsup (84 ± 34% and 82 ± 33%). While FVC and ALSFRS-R declined in parallel, SNIPsitt measures declined significantly less compared to ALSFRS-R (p < 0.05) and FVC (p < 0.001) up to 4 months after enrollment. Over 50% of patients still had values equal to or above baseline SNIPsitt measures after 3 months despite abnormal baseline values.

CONCLUSIONS

The delayed decline in SNIP measurements suggests a learning effect over time. The optimal number of SNIPs in ALS clinical trials has yet to be determined. SNIP measures should be used with caution in trials with a lead-in design.

Southwest Oncology Group study S0413: a phase II trial of lapatinib (GW572016) as first-line therapy in patients with advanced or metastatic gastric cancer

BACKGROUND

Lapatinib (GW572016) is a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/ErbB2), which are reported as overexpressed in 15%-45% of gastric cancers, making them potential targets.

PATIENTS AND METHODS

The primary objective of this study was to assess response rate. Secondary objectives included overall survival (OS), toxicity, and the relationship of EGFR, ErbB2, and markers of angiogenesis with clinical outcome. Lapatinib was administered to chemonaive metastatic gastric cancer patients at a dose of 1500 mg orally daily for 28 days.

RESULTS

The study enrolled 47 patients from February 2005 until May 2006. Four patients (9%) had a confirmed partial response (PR), 1 (2%) had an unconfirmed PR, and 10 (23%) had stable disease. Median (95% confidence interval) time to treatment failure was 1.9 (1.6-3.1) months and OS was 4.8 (3.2-7.4) months. Significant adverse events: one grade 4 cardiac ischemia/infarction, one grade 4 fatigue, and one grade 4 emesis. One treatment-related death was due to central nervous system ischemia. An exploratory analysis of markers revealed gene expression of HER2, interleukin (IL)-8 and genomic polymorphisms IL-8, and vascular endothelial growth factor correlated with OS.

CONCLUSIONS

Lapatinib is well tolerated, with modest single-agent activity in advanced/metastatic gastric cancer patients. Potential molecular correlatives were identified which warrant further validation.

Tetrahydrocannabinol (THC) for cramps in amyotrophic lateral sclerosis: a randomised, double-blind crossover trial

BACKGROUND

Many patients with amyotrophic lateral sclerosis (ALS) experience cramps during the course of the disease but so far, none of the medications used has been of proven benefit. The objective was to determine the effect of orally administered tetrahydrocannabinol (THC) on cramps in ALS patients.

METHODS

The authors conducted a randomised, double-blind, placebo-controlled crossover trial in 27 ALS patients suffering from moderate to severe (visual analogue scale (VAS); VAS≥4) daily cramps. There were 7 women and 20 men with a mean age of 57 years and a mean functional ALS score (ALSFRS-R) of 38.4. Patients were randomly assigned to receive 5 mg THC twice daily followed by placebo or vice versa. Each treatment period lasted for 2 weeks and was preceded by a 2-week drug-free observation period (run-in, wash-out period respectively). The primary outcome measure was change in cramp intensity as assessed by a VAS. Secondary outcome measures included the number of cramps per day, number of cramps during daytime and bedtime, intensity of fasciculations (VAS) as well as validated measures of quality of life (ALSAQ-40), quality of sleep (SDQ), appetite (FAACT) and depression (HADS).

RESULTS

Complete data were available from 22 patients. THC was well tolerated. There was no evidence for a treatment effect on cramp intensity, number of cramps, fasciculation intensity or any of the other secondary outcome measures.

CONCLUSIONS

This interventional study with orally administered THC 5 mg twice daily did not demonstrate subjective improvement of cramp intensity in ALS patients.

Prognostic value of regulatory T cells, lymphoma-associated macrophages, and MUM-1 expression in follicular lymphoma treated before and after the introduction of monoclonal antibody therapy: a Southwest Oncology Group Study

BACKGROUND

The purpose was to examine the prognostic impact of features of tumor cells and immune microenvironment in patients with follicular lymphoma treated with and without anti-CD20 monoclonal antibody therapy.

PATIENTS AND METHODS

Tissue microarrays were constructed from archived tissue obtained from patients on three sequential Southwest Oncology Group (SWOG) trials for FL. All three trials included anthracycline-based chemotherapy. Anti-CD20 monoclonal antibodies were included for patients in the latter two trials. Immunohistochemistry was used to study the number and distribution of cells staining for forkhead box protein P3 (FOXP3) and lymphoma-associated macrophages (LAMs) and the number of lymphoma cells staining for myeloma-associated antigen-1 (MUM-1). Cox proportional hazards regression was used to evaluate the association between marker expression and overall survival (OS).

RESULTS

The number or pattern of infiltrating FOXP3 cells and LAMs did not correlate with OS in sequential SWOG studies for FL. The presence of MUM-1 correlated with lower OS for patients who received monoclonal antibody but not for those treated with chemotherapy alone.

CONCLUSIONS

Immune cell composition of lymph nodes did not correlate with OS in this analysis of trials in FL. The mechanism of the observed correlation between MUM-1 expression and adverse prognosis in patients receiving monoclonal antibody therapy requires confirmation.

SWOG S0354: A phase II trial of CNTO328, a monoclonal antibody against interleukin-6 (IL-6), in chemotherapy pretreated patients (pts) with castration- resistant prostate cancer (CRPC)

5143

Background: IL-6 facilitates cancer cell survival via pleiotrophic effects on proliferation, apoptosis, angiogenesis, differentiation, and chemo-resistance. A multicenter phase II study of CNTO328 in chemo pretreated CRPC pts was conducted. Methods: Eligible pts had one prior chemotherapy, Zubrod performance status 0–2, and adequate end-organ function. Regimen: CNTO328 6 mg/kg IV q2 weeks x 12 cycles. Response assessment was q6 weeks. Primary endpoint was PSA response rate (RR) defined as ≥50% reduction. Accrual was completed in 2 stages, with planned accrual of 20 eligible pts in the first stage and 40 overall. Plasma cytokines were measured by Luminex in 44 pts. Results: Of 62 pts, 54 were eligible; all had received prior taxane therapy. Two (3.7%; 95% CI: 0.5%, 12.8%) had PSA response. Of 47 pts evaluable by RECIST, none had a response and 10 (21%) had stable disease (SD). With median follow-up of 6.6 months, median progression-free survival is 1.6 months (95% CI: 1.6, 1.7). Grade 4 toxicity included 1 case of DIC and 1 CNS ischemia; grade 3 toxicities included elevated AST (1), gastritis/esophagitis (2), thrombocytopenia (2), pain (2), leucopenia (1), and neuropathy (2). Median baseline IL-6 levels were 12.5 pg/mL (IQR: 2.5, 41.5). Pts with levels >12.5 pg/mL had worse 6-month survival vs. < 12.5 pg/mL (53% vs 94%, p = 0.02). Post-cycle 1, IL-6 levels were > 250-fold higher, indicating antibody-target complex formation. 33/39 pts had a decline in C-reactive protein (CRP) plasma levels at 6 weeks. Conclusions: CNTO328 was well-tolerated and resulted in a PSA RR of 3.7% and RECIST SD rate of 21%. Declining CRP levels during treatment reflect biologic activity. Elevated baseline IL-6 levels portend a poor prognosis. Additional translational studies will be presented. Additional study of CNTO328 in combination may be warranted.

[Table: see text]

Chemoradiation of resected gastric cancer: A 10-year follow-up of the phase III trial INT0116 (SWOG 9008)

4515

Background: INT0116 (SWOG 9008) was a prospectively randomized phase III trial of postoperative adjuvant therapy utilizing 5-FU/leucovorin plus external beam radiation in 582 eligible cases of resected stage IB-IV(M0) stomach and gastroesophageal junction cancers. Initial results (NEJM 345: 725, 2001) showed both overall and disease free survivals improved by chemoradiation. Methods:We now report INT0116 results with >10years median follow-up. Exploratory subset outcomes are also reported. Results: INT0116 continues to show benefit for chemoradiation with hazard ratios (HR) for survival (HR=1.32, p=.004) and disease free survival (HR=1.51, p<.001) favoring chemoradiation. Subset analyses were performed for sex, race, T and N stage, D-level of surgical resection, tumor location (proximal or other), histology (intestinal or diffuse) and Maruyama index. Chemoradiation benefited all subsets with the exceptions of women and diffuse histology. In women the HR for therapy was 1.0(0.68–1.45). The HR for therapy in diffuse histology cases was 0.97(0.62–1.40). Interaction between these factors is suggested as women were significantly more likely to have diffuse histology than men (56% versus 33%). A multivariate analysis of sex and histology did not detect an effect of sex once histology was included. These data suggest that sex may not be an independent variable for lack of response to chemoradiation but that diffuse histology may be. Long term toxicities were examined. Thirty-five second tumors occurred in 31 cases. Twenty-two occurred in chemoradiation cases and 9 in surgery only cases. Second tumors represented a spectrum of types of neoplasms commonly occurring in this age group (median age 60 years). Excessive numbers of tumors known to be caused by radiation and/or chemotherapy were not noted. More tumors may have occurred in the treated patients since their death rates were less than surgery only cases. Conclusions: With >10 years median follow-up, survival remains improved in stage IB-IV (M0) gastric cancer cases treated with post-operative chemoradiaiton. All subsets benefit from this treatment with the exception of cases with diffuse histology. Women may be more likely to have diffuse histology gastric cancers. No increases in late toxic effects were noted.

No significant financial relationships to disclose.

Gene expression levels of HER2 and IL-8 and polymorphism in IL-8 associated with clinical outcome in advanced or metastatic gastric cancer treated with lapatinib in SWOG 0413 trial

4647

Background: Lapatinib (GW572016) is a dual tyrosine kinase inhibitor of EGFR and HER2. In SWOG0413 trial, advanced or metastatic gastric cancer patients were treated with lapatinib. In this study, we investigated whether gene expressions and polymorphisms of EGF and angiogenesis pathway genes were associated with clinical outcome in the patients enrolled in SWOG0413 trial. Methods: A total of 46 patients were enrolled in SWOG0413 trial and treated with lapatinib. Blood and tissue samples were available from 42 and 37 patients, respectively. RT-PCR was performed for intratumoral gene expression levels of EGFR, HER2, VEGF, IL-8, COX2 and cyclin D1 genes. We also analyzed 8 polymorphisms in the EGF, EGFR, HER2, VEGF, IL-8, COX2 and cyclin D1 genes by PCR-RFLP. Results: Patients who have lower IL-8 [median overall survival (OS), 6 vs 3 months, p=0.03] and higher HER2 (6 vs 3 months, p=0.005) gene expression levels showed better OS. According to gene polymorphisms, patients who have A allele of IL-8 T251A polymorphism showed improved OS (A/A, 10 months vs T/A, 5 months vs T/T 3 months, p=0.04). And patients with A allele of IL-8 T251A and T allele of VEGF C936T polymorphisms showed better response rates (p<0.01, p<0.01, respectively). All other polymorphisms and gene expressions did not show significant association with clinical outcome. Conclusions: Our results suggest that intratumoral gene expression levels of HER2 and IL-8 and polymorphism in IL-8 are potential molecular predictors for survival in patients with advanced or metastatic gastric cancer treated with lapatinib. And polymorphisms in IL-8 and VEGF genes may be potential markers in predicting response in this population. A larger prospective study is needed to validate and confirm these preliminary findings.

[Table: see text]

S0413: A phase II SWOG study of GW572016 (lapatinib) as first line therapy in patients (pts) with advanced or metastatic gastric cancer

4621

Background: GW572016 is a dual tyrosine kinase inhibitor of EGFR and HER2/ErbB2. Overexpression of EGFR and ErbB2 has been described in 15 to 45% of gastric cancer, making this a potential target in advanced/metastatic tumors. Methods: The primary objective of this study was to assess the response rate (confirmed complete (CR) and partial responses (PR)). Secondary objectives included time to treatment failure (TTF), overall survival (OS), toxicities and the relationship of EGFR, ErbB2, and markers of angiogenesis with clinical outcome in patients treated with GW572016. A two-stage design was used to detect a difference in the null hypothesis of 5% response probability and the alternative 20% response probability. If at least one response occurred after the first 20 pts, another 20 were to be accrued. GW572016 was administered to chemonaiive metastatic gastric cancer patients at a dose of 1,500 mg orally daily. A cycle was defined as 28 days of therapy, and patients were staged after 2 cycles of treatment. Results: The study met its first stage goal, and continued until full accrual. The study accrued 47 pts from February 2005 until May 2006. Two patients lacked required tissue/blood submission but are included in this clinical analysis. One patient did not receive treatment and is not analyzable. Pt characteristics: male/female30/16 (65%/35%); median age 68.7 years (range 38.9 - 90). Significant toxicities: 1 grade 4 cardiac ischemia/infarction, 2 grade 4 fatigue, 1 grade 4 vomiting. There was one treatment related death due to CNS ischemia. Three pts (7%) had a confirmed PR and 2 (5%) unconfirmed PR, and 9 (20%) had stable disease. Median TTF was 2 months, and OS was 5 months. Molecular correlative data was available on 42 pts. Conclusions: GW572016 is a well tolerated regimen with modest single-agent activity in pts with advanced/metastatic gastric cancer. Although, GW572016 did not meet the primary endpoint, this targeted agent may warrant further investigation in combination regimens. Molecular correlatives will be reported in a separate abstract.

No significant financial relationships to disclose.

Comprehensive diagnosis of Rett's syndrome relying on genetic, epigenetic and expression evidence of deficiency of the methyl-CpG-binding protein 2 gene: study of a cohort of Israeli patients

BACKGROUND

Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations.

OBJECTIVE AND METHODS

To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays.

RESULTS AND CONCLUSION

A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.

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.

Comprehensive diagnosis of Rett's syndrome relying on genetic, epigenetic and expression evidence of deficiency of the methyl-CpG-binding protein 2 gene: study of a cohort of Israeli patients

BACKGROUND

Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations.

OBJECTIVE AND METHODS

To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays.

RESULTS AND CONCLUSION

A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.

Analysis of the PixA inclusion body protein of Xenorhabdus nematophila

The symbiotic pathogenic bacterium Xenorhabdus nematophila produces two distinct intracellular inclusion bodies. The pixA gene, which encodes the 185-residue methionine-rich PixA inclusion body protein, was analyzed in the present study. The pixA gene was optimally expressed under stationary-phase conditions but its expression did not require RpoS. Analysis of a pixA mutant strain showed that PixA was not required for virulence towards the insect host or for colonization of or survival within the nematode host, and was not essential for nematode reproduction. The pixA gene was not present in the genome of Xenorhabdus bovienii, which also produces proteinaceous inclusions, indicating that PixA is specifically produced in X. nematophila.

Prospective noise induced changes to hearing among construction industry apprentices

AIMS

To characterise the development of noise induced damage to hearing.

METHODS

Hearing and noise exposure were prospectively monitored among a cohort of newly enrolled construction industry apprentices and a comparison group of graduate students, using standard pure tone audiometry and distortion product otoacoustic emissions (DPOAEs). A total of 328 subjects (632 ears) were monitored annually an average of 3.4 times. In parallel to these measures, noise exposure and hearing protection device (HPD) use were extensively monitored during construction work tasks. Recreational/non-occupational exposures also were queried and monitored in subgroups of subjects. Trade specific mean exposure L(eq) levels, with and without accounting for the variable use of hearing protection in each trade, were calculated and used to group subjects by trade specific exposure level. Mixed effects models were used to estimate the change in hearing outcomes over time for each exposure group.

RESULTS

Small but significant exposure related changes in DPOAEs over time were observed, especially at 4 kHz with stimulus levels (L1) between 50 and 75 dB, with less clear but similar patterns observed at 3 kHz. After controlling for covariates, the high exposure group had annual changes in 4 kHz emissions of about 0.5 dB per year. Pure tone audiometric thresholds displayed only slight trends towards increased threshold levels with increasing exposure groups. Some unexpected results were observed, including an apparent increase in DPOAEs among controls over time, and improvement in behavioural thresholds among controls at 6 kHz only.

CONCLUSIONS

Results indicate that construction apprentices in their first three years of work, with average noise exposures under 90 dBA, have measurable losses of hearing function. Despite numerous challenges in using DPOAEs for hearing surveillance in an industrial setting, they appear somewhat more sensitive to these early changes than is evident with standard pure tone audiometry.

Intravenous immunoglobulins in peripheral neuropathy associated with vasculitis

BACKGROUND

Peripheral neuropathy is a prominent feature of the systemic and secondary vasculitides. Usually, it is responsive to corticosteroids, but in certain cases it may be resistant to corticosteroid or immunosuppressive treatment, or both.

OBJECTIVE

To present patients who exhibited various inflammatory diseases accompanied with vasculitic peripheral neuropathies for which intravenous immunoglobulin (IVIg) was used for treatment.

METHODS

Six patients with Sjögren's syndrome, systemic lupus erythematosus (SLE), vaccination induced vasculitis, Churg-Strauss vasculitis, mixed cryoglobulinaemia associated with hepatitis C infection, or sarcoidosis were included. All developed vasculitic peripheral neuropathy, and were treated with high dose IVIg (2 g/kg body weight). The patients were followed up for 1-5 years after this treatment.

RESULTS

In four patients (Sjögren's syndrome, Churg-Strauss vasculitis, SLE, and vaccination induced vasculitis) the neuropathy resolved after IVIg treatment.

CONCLUSION

IVIg may be beneficial in cases of resistant vasculitic peripheral neuropathy. IVIg should probably be considered as a sole or adjuvant treatment for patients with contraindications to conventional treatment, or alternatively, for patients in whom conventional treatment has failed.

Hematopoietic progenitor cells as targets for non-invasive prenatal diagnosis: detection of fetal CD34+ cells and assessment of post-delivery persistence in the maternal circulation

Culture expansion of fetal cells from the maternal circulation will provide an increased number of cells for non-invasive prenatal diagnosis. Hematopoietic CD34+ cells are potential candidates for this application. More information is needed regarding the frequency of these cells and the phenomenon of post-delivery persistence in the maternal circulation. In this study we assessed the number of fetal CD34+ cells in the maternal circulation, the effect of culture expansion on the number of fetal cells and the persistence of fetal CD34+ cells from previous pregnancies. Fetal cells were identified by the presence of Y-chromosome sequences detected by FISH and nested PCR. Fetal CD34+ cells were detected in all samples from women carrying a male fetus. A low number of residual fetal cells from previous pregnancies was detected (1-3 XY cells in 20 ml blood) in less than 1/3 of the samples from both non-pregnant women and those pregnant with a female fetus. Culturing of CD34+ cells resulted in a significant increase in fetal cell numbers. However, the number of fetal cells persisting from previous pregnancies also increased after culture. It is proposed that information derived from CD34+ cells could potentially support data derived from other cell types for more accurate non-invasive prenatal diagnosis.

Germline mutations in the PTEN gene in Israeli patients with Bannayan-Riley-Ruvalcaba syndrome and women with familial breast cancer

Germline mutations in BRCA1 or BRCA2 account for the majority of inherited breast cancer cases. Yet, in up to 40% of familial breast cancer cases, no mutations can be detected in either gene. Germline mutations in PTEN underlie two inherited syndromes: Cowden disease (CD) and Bannayan-Riley-Ruvalcaba syndrome (BRRS). The known association of CD with breast cancer risk made it plausible that germline mutations within PTEN may play a role in inherited predisposition to breast cancer. The nine coding exons of the PTEN gene were screened for harboring germline mutations using denaturing gradient gel electrophoresis (DGGE) complemented by sequencing, in two subsets of Israeli patients: 12 patients clinically diagnosed with BRRS, and 89 women with an apparent inherited predisposition to breast cancer, some with salient features of CD. Two of three familial BRRS patients exhibited novel germline mutations in PTEN: a missense mutation changing methionine to arginine at codon 134, and insertion of two nucleotides (CA) at cDNA position 1215 resulting in a frameshift at codon 61 and a premature stop at codon 99. Among 89 high-risk women, two missense mutations were detected in exon 4: A to C change at cDNA position 1279 resulting in a change of aspargine to threonine at codon 82 (N82T), and a G to an A alteration in 1269 which alters threonine to alanine at codon 78 (T78A), a non-conservative missense mutation. This study suggests that PTEN does not play a major role in predisposing to hereditary breast cancer in Israeli women, and that detection of PTEN mutations in BRRS patients is more likely in familial cases.

Genotyping of Israeli infertile men with idiopathic oligozoospermia

Microdeletions of the long arm of the Y chromosome involving the azoospermia factor (AZF) region are associated with severe oligo- or azoospermia. Abnormal androgen receptor (AR) structure or function has also been implicated in male infertility. To assess the contribution of these genetic defects to male infertility, 61 Israeli men with severe oligo- (n = 15) or azoospermia (n = 46), were screened for Y chromosome microdeletions, and the AR-(CAG)n repeat length. Fifty fertile Israeli men were similarly analyzed. PCR amplification of 20-54 simple tag sequences (STSs) located at Yq was used to determine the rate and extent of Y chromosome microdeletions. PCR with primers flanking the AR-(CAG)n region and subsequent size fractionation on gradient acrylamide gels were used to determine AR-(CAG)n length. Five azoospermic individuals (5/61-8.2% and 5/46-10.8% of azoospermic patients) displayed Y chromosome microdeletions. The mean CAG repeat number in infertile men was 18.6 +/- 3.0 compared with 16.6 + 2.7 in fertile men (n = 50), a statistically significant difference (p = 0.003). Y chromosome microdeletions contribute to male infertility in our azoospermic population, and the mean length of the AR-CAG is significantly longer in our infertile population than in fertile men.

Association between anorexia nervosa and the hsKCa3 gene: a family-based and case control study

Familial and twin studies have suggested that anorexia nervosa (AN) is a multifactorial disorder with a substantial genetic contribution. The hSKCa3 potassium channel gene, which contains polymorphic CAG repeats in the coding region and is involved in the regulation of neuronal activity, may be a candidate gene for AN because alleles with longer repeats have been found to be associated with mental disorders. Forty Israeli AN family trios were genotyped for the hSKCa3 CAG repeat polymorphism using the haplotype relative risk (HRR) method. The distribution of alleles transmitted to the patients was found to be significantly different from that of the non-transmitted parental alleles, with the longer alleles being over-represented in the patients (Wilcoxon rank test, P = 0.008). The transmission disequilibrium test (TDT) revealed that longer (>19) repeat alleles were preferentially transmitted to AN patients (McNemar's chi(2) = 10.31, P = 0.0013). These results were corroborated by comparing the distribution of alleles between patients and healthy controls (Mann-Whitney test, P = 0.005). Our study suggests that the longer repeat alleles of the hSKCa3 gene may contribute to the genetic susceptibility to AN.

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.

Comparative genomic hybridization analysis of radiation-associated and sporadic meningiomas

Ionizing irradiation to the skull is a known risk factor for meningioma development. To gain insight into the molecular mechanisms that underlie radiation-associated meningioma (RAM), we characterized the somatic genetic alterations in 16 RAMs by using comparative genomic hybridization and compared the pattern of alterations with 17 nonradiation-associated meningiomas (non-RAM). Most tumors (29/33;87.9%) displayed at least one DNA copy number alteration, and 11 out of 33 (33%) exhibited four or more changes. The mean number of DNA copy number changes was similar in RAMs (2.4+/-1.9) and in non-RAMs (2.5+/-1.9). The most common DNA losses were noted in chromosome 22 (56.2% in RAM, and 47% in non-RAM) and chromosome 1 (37.5% in RAM and 35.3% in non-RAM), with no significant differences between the two groups. Noteworthy, gain in DNA copy number of chromosomes 8 and 12 was detected in two RAM tumors only. In conclusion, no significant differences were noted between RAMs and non-RAMs regarding the number of genetic changes and the extent and frequency of chromosomes 1 and 22 losses. These preliminary data suggest that the tumorogenic pathways of meningioma formation are similar, regardless of previous skull irradiation.

Analysis of explants and causes of mortality during long-term follow-up of the Toronto stentless porcine valve

The long-term status of stentless porcine valves has not yet been defined.

METHODS

447 patients were followed at 6 IDE sites up to 10 years (total follow-up, 2024.3 pt years; mean, 4.5 years): 35% were over 70 years and 41% underwent concomitant coronary artery bypass grafting.

RESULTS

10 patients underwent reoperation for valve explant (0.5%/pt year) because of severe aortic incompetence (AI) from dilatation of the aorta, sinotubular junction or sinus of Valsalva with torn commissures or cusps (8 patients) and endocarditis with abscess and dehiscence (2 patients). Six of 8 patients with late AI had bicuspid native aortic valves (mean age, 39.8 years). Overall freedom from reoperation was 95.2%. Freedom from structural deterioration was 96.1% at 7 years (98.0% for patients >60 years). Of 49 late deaths (2.5%/pt year), 9 were valve related (0.5%/pt year), 10 cardiac related, and 30 because of noncardiac causes. Valve-related deaths were because of endocarditis (3), CVA (1), redo surgery (1), or unknown reasons (4). Noncardiac deaths were due mainly to cancer (19/30). At seven years, freedom from all cause death was 81.8% and freedom from valve-related death 96.9%.

CONCLUSIONS

Late mortality after stentless valve replacement has been primarily because of comorbidities present at surgery or developing later. The Toronto stentless porcine valve is associated with a low rate of reoperation and valve-related death.

Eight-year hemodynamic follow-up after aortic valve replacement with the Toronto SPV stentless aortic valve

The hemodynamic performance of stentless aortic bioprostheses has been well described during the first few months after surgery. The purpose of the present study was to describe the hemodynamic performance of the Toronto SPV valve (St. Jude Medical, Inc, St. Paul, MN) in a multicenter trial through 8 years. The long-term study of the Toronto SPV valve includes 447 consecutive patients from 6 investigative centers. Echocardiographic follow-up was performed at specified intervals, with quantitative analysis performed at a centralized core laboratory. Mean transvalvular gradient decreased significantly between discharge and 6 months, between 6 months and 1 year, and between 1 year and 2 years after surgery, without further significant change. The effective orifice area increased significantly early after surgery and continued to increase through 6-year follow-up. The left ventricular (LV) stroke volume increased progressively from discharge through 6-year follow-up. The LV mass index decreased significantly from discharge through 3 years after surgery and stabilized through 5 years. There was a gradual increase in LV outflow tract diameter between 1 year and 6 years after surgery. The prevalence of any aortic regurgitation (AR) (including trivial) and > or = mild AR increased significantly between discharge and 6-year to 8-year follow-up. However, the prevalence of > or = moderate AR remained very low at 6 years (2.6%) and 8 years (4.5%) after surgery. In conclusion, the Toronto SPV stentless tissue aortic valve is associated with excellent hemodynamics early after surgery and through 8 years after surgery. LV mass decreases early, and returns to within the range of normal by 1 year after surgery. There is evidence of continued LV mass regression involving the LV outflow tract, potentially contributing to a small but significant late improvement in hemodynamics. The prevalence of significant AR remains low through 8 years.

A gene causing autosomal recessive cataract maps to the short arm of chromosome 3

BACKGROUND

Fourteen loci have been associated with autosomal dominant cataract, but only one with the recessive form of the disease.

OBJECTIVES

To find the chromosomal location of a gene causing autosomal recessive cataract in three inbred Arab families.

METHODS

A single nucleotide polymorphism-based genome-wide search, with the Effvmetrix GeneChip HuSNP genotyping array, was performed on a pooled DNA sample from six affected family members in a search for regions showing homozygosity. Using conventional microsatellite markers, regions of homozygosity were further analyzed in all the families.

RESULTS

A region on chromosome 3p spanning 43 megabases showed homozygosity with 13 consecutive SNPs. Three microsatellite markers from this region yielded lod scores > 3.00. A maximal two-point lod of 4.83 was obtained with the marker D3S1298 at theta = 0.004. Haplotype analysis placed the disease gene in a 20 Mb interval between D3S1768 and D3S2409.

CONCLUSIONS

A gene causing autosomal recessive cataract maps to the short arm of chromosome 3.

Quantification of gastric emptying and duodenogastric reflux stroke volumes using three-dimensional guided digital color Doppler imaging

OBJECTIVE

To develop a non-invasive method for evaluating gastric emptying and duodenogastric reflux stroke volumes using three-dimensional (3D) guided digital color Doppler imaging.

METHODS

The technique involved color Doppler digital images of transpyloric flow in which the 3D position and orientation of the images were known by using a magnetic location system.

RESULTS

In vitro, the system was found to slightly underestimate the reference flow (by average 8.8%). In vivo (five volunteers), stroke volume of gastric emptying episodes lasted on average only 0.69 s with a volume on average of 4.3 ml (range 1.1-7.4 ml), and duodenogastric reflux episodes on average 1.4 s with a volume of 8.3 ml (range 1.3-14.1 ml).

CONCLUSION

With the appropriate instrument settings, orientation determined color Doppler can be used for stroke volume quantification of gastric emptying and duodenogastric reflux episodes.

Autosomal recessive catecholamine- or exercise-induced polymorphic ventricular tachycardia: clinical features and assignment of the disease gene to chromosome 1p13-21

BACKGROUND

Catecholaminergic polymorphic ventricular tachycardia (PVT) is characterized by episodes of syncope, seizures, or sudden death in response to physiological or emotional stress. In 2 families with autosomal dominant inheritance, the disease gene was mapped to chromosome 1q42-43. The objectives of this study were to characterize the clinical features of the disease in a Bedouin tribe from Israel and to map the disease gene.

METHODS AND RESULTS

In this Bedouin tribe, 9 children (age, 7+/-4 years) from 7 related families have died suddenly during the past decade, and 12 other children suffered from recurrent syncope and seizures starting at the age of 6+/-3 years. Parents of affected individuals were asymptomatic and were all related (first-, second-, or third-degree cousins). Segregation analysis suggested autosomal recessive inheritance. All 12 symptomatic patients and 1 asymptomatic sibling (mean age, 13+/-7 years) were found to have a relative resting bradycardia (64+/-13 bpm, versus 93+/-12 bpm in the unaffected siblings), as well as PVT induced by treadmill or isoproterenol infusion and appearing at a mean sinus rate of 110+/-10 bpm. Patients responded favorably to treatment with beta-blockers. A genome-wide search using polymorphic DNA markers mapped the disease locus to a 16-megabase interval on chromosome 1p13-21. A maximal lod score of 8.24 was obtained with D1S189 at theta=0.00. Sequencing of KCND3, a gene that encodes an I(tO) potassium channel transporter, did not reveal any significant sequence alterations.

CONCLUSIONS

This unique form of autosomal recessive PVT affects young children and may be lethal if left untreated. Linkage analysis maps this disorder to chromosome 1p13-21.

Renal dysfunction after cardiac surgery

OBJECTIVE

To assess the causes and outcomes of patients with postcardiac surgery renal dysfunction.

PATIENTS AND METHODS

A large cardiovascular data- base including pre-, peri- and postoperative serum creatinine concentrations from 2214 consecutive cardiac surgery patients was analyzed.

RESULTS

Sixty-nine patients developed postoperative renal dysfunction, defined as at least a 15 mL/min decline in the creatinine clearance rate resulting in a value of less than 40 mL/min. These patients were significantly older, and had a higher incidence of previous cardiac surgery, diabetes, obesity, peripheral vascular disease, hypertension and poor ventricular function. Postoperatively, these patients had a higher occurrence of low output syndrome and myocardial infarction. Stepwise logistic regression predictors of postoperative renal dysfunction included the following: postoperative low output syndrome; repeat cardiac surgery; being older than 65 years; having diabetes; having poor left ventricular function; and having had valve surgery. Preoperative renal dysfunction (defined as a creatinine clearance of less than 40 mL/min) was not found to be one of the predictors. The mean creatinine concentrations of patients with mild postoperative renal dysfunction (defined as a creatinine concentration of less than 200 mmol/L on the fourth or fifth postoperative day) decreased significantly at the fifth postoperative day, while that of patients with severe postoperative renal dysfunction rose to a mean of 300 mmol/L six months postoperatively. The incidence of late dialysis (defined as a need for dialysis after postoperative day 10) approached 30% among patients with severe postoperative renal dysfunction and only 2% among patients with mild postoperative renal dysfunction. The early mortality rate (during the first postoperative month) was similar in both groups and approached 30%.

CONCLUSIONS

Patients who develop postoperative renal dysfunction have a high mortality rate. Postoperative low cardiac output is the most important cause of postoperative renal dysfunction and, therefore, should be avoided. Patients with creatinine concentrations of less than 200 mmol/L at postoperative day 4 or 5 will probably resume normal renal function. Patients with creatinine concentrations of more than 200 mmol/L at days 4 and 5 have a 30% chance of needing long term dialysis.

Mutational analyses of BRCA1 and BRCA2 in Ashkenazi and non-Ashkenazi Jewish women with familial breast and ovarian cancer

In Ashkenazi (East European) Jews, three predominant mutations in BRCA1 (185delAG and 5382insC) and BRCA2 (6174delT) account for the majority of germline mutations in high-risk breast and/or ovarian cancer families. Among non-Ashkenazi Jews, the 185delAG, Tyr978Ter, and a handful of "private" mutations have been reported anecdotally within both genes. In this study we attempted to determine the spectrum of BRCA1 and BRCA2 mutations in high-risk Jewish individuals, non-carriers of any of the predominant Jewish mutations. We employed multiplex PCR and denaturing gradient gel electrophoresis (DGGE) analysis for BRCA2, and combined denaturing high performance liquid chromatography (DHPLC) and protein truncation test (PTT) for BRCA1, complemented by DNA sequencing. We screened 47 high-risk Jewish individuals, 26 Ashkenazis, and 21 non-Ashkenazis. Overall, 13 sequence alterations in BRCA1 and eight in BRCA2 were detected: nine neutral polymorphisms and 12 missense mutations, including five novel ones. The novel missense mutations did not co-segregate with disease in BRCA1 and were detected at rates of 6.25% to 52.5% in the general population for BRCA2. Our findings suggest that except for the predominant mutations in BRCA1 and BRCA2 in Jewish individuals, there are only a handful of pathogenic mutations within these genes. It may imply novel genes may underlie inherited susceptibility to breast/ovarian cancer in Jewish individuals.

Prenatal diagnosis of a novel COL1A1 mutation in osteogenesis imperfecta type I carried through full term pregnancy

Prenatal diagnosis was performed in a family where the father has osteogenesis imperfecta (OI) type I, with a novel mutation in the COL1A1 gene: a C to T change at position c3076 (c.3076C-->T) leading to a change of arginine at codon 848 to a stop codon (R848X). Prenatal diagnosis by chorionic villous sampling (CVS) was performed during the fourth pregnancy, and revealed that the fetus is a carrier of the same COL1A1 mutation. The possibility of phenotypic variability was discussed with the parents. They elected to carry the pregnancy to term, and a male child with mild OI was born. This is the first reported case where OI was diagnosed prenatally, and the parents opted to carry the pregnancy to term. It illustrates the potential use of DNA-based analysis for early prenatal diagnosis of OI, and the complexities of genetic counselling.

A nonsense mutation (W9X) in CRYAA causes autosomal recessive cataract in an inbred Jewish Persian family

PURPOSE

To identify the genetic defect causing autosomal recessive cataract in two inbred families.

METHODS

Linkage analysis was performed with polymorphic markers close to 14 loci previously shown to be involved in autosomal dominant congenital cataract. In one of the families a gene segregating with the disease was analyzed by single-strand conformation polymorphism (SSCP) and eventually sequenced.

RESULTS

Three polymorphic markers close to the CRYAA gene located on chromosome 21q segregated with the disease phenotype in one of the families, but not in the other. Sequencing of the CRYAA in this Jewish Persian family revealed a G-to-A substitution, resulting in the formation of a premature stop codon (W9X).

CONCLUSIONS

A nonsense mutation in the CRYAA gene causes autosomal recessive cataract in one family. This constitutes the first description of the molecular defect underlying nonsyndromic autosomal recessive congenital cataract. That there was no linkage to this locus in another family provides evidence for genetic heterogeneity.

Coronary arteries from human cardiac allografts with chronic rejection contain oligoclonal T cells: persistence of identical clonally expanded TCR transcripts from the early post-transplantation period (endomyocardial biopsies) to chronic rejection (coronary arteries)

Chronic cardiac allograft rejection presents pathologically as graft arteriosclerosis (GA) characterized by recipient T cell and monocyte infiltration. To determine whether oligoclonal T cells are present in coronary arteries of cardiac allografts from patients with GA, we conducted sequencing analysis of beta-chain TCR transcripts from these explanted coronary arteries using the nonpalindromic adaptor-PCR. Substantial proportions of identical beta-chain TCR transcripts in three of five patients were observed, clearly demonstrating the presence of oligoclonal T cells. TCR transcripts from the arteries of two other patients were relative heterogeneous. High proportions of identical CDR3 beta-chain TCR motifs were found in each patient. GENEBANK/EMBL/SWISS PROT database comparison of all sequences revealed that these beta-chain TCR transcripts were novel. Using Vbeta-specific PCR (independent amplification), we found in patient GA03 that the TCR transcript that was clonally expanded in the left anterior descending artery after nonpalindromic adaptor-PCR was also clonally expanded in the right coronary artery of the same allograft. These results demonstrate that this TCR transcript was clonally expanded at different anatomic sides of the cardiac allograft in a systemic manner. In two patients identical beta-chain TCR transcripts that were found to be clonally expanded in the coronary arteries of their explanted cardiac allografts were also found to be clonally explanted in endomyocardial biopsies collected 17 and 21 mo earlier from each patient. The presence of oligoclonal populations of T cells in the rejected graft suggest that these T cells have undergone specific Ag-driven proliferation and clonal expansion early on within the graft and persist throughout the post-transplantation period.

Comparative genomic hybridization in inherited and sporadic ovarian tumors in Israel

To gain an understanding of the molecular mechanisms of ovarian cancer, we analyzed 16 ovarian tumors from Jewish Israeli patients by comparative genomic hybridization: 12 invasive epithelial tumors (including three BRCA1 and one BRCA2 mutation carriers), 2 primary peritoneal carcinomatosis, 1 pseudomyxoma peritoneii tumor, and 1 sertoli cell tumor. We similarly analyzed 1 normal ovary from a BRCA1 mutation carrier, and 3 metastases. The most common abnormalities in epithelial tumors were amplification of 8q22.1-ter (8/12, 66.6%), 1q22-32.1 (5/12, 41.6%), 3q, 10p (4/12, 33.3% for each), and deletions of 9q (5/12, 41.6%) and 16q21-24 (4/12, 33.3%). All 3 BRCA1 mutation carriers and 2 of 8 sporadic cases displayed 9q deletion, and 2 of 3 BRCA1 mutation carriers, but none of the sporadic cases, had deletion of chromosome 19. The range of genetic changes in primary peritoneal tumors and epithelial ovarian cancers was similar, though the mean number of alterations in the former was less (3.5/tumor versus 8/tumor). Our preliminary results may indicate that inherited predisposition to ovarian cancer possibly entails preferential somatic deletions of chromosomes 9 and 19.

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.

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.

Noonan syndrome: a cryptic condition in early gestation

Noonan syndrome is one of the most common of genetic syndromes and manifests at birth, yet it is usually diagnosed during childhood. Although prenatal diagnosis of Noonan syndrome is usually not possible, in a few cases the ultrasonographic findings suggested the diagnosis in utero. Reported sonographic clues include septated cystic hygroma, hydrothorax, polyhydramnios, and cardiac defects, such as pulmonic stenosis and hypertrophic cardiomyopathy. During a 6-year period, 46,224 live-born infants were delivered at the Chaim Sheba Medical Center. Seven newborn infants and four fetuses were found to have Noonan syndrome. One fetus showed transient nuchal translucency of 4 mm and bilateral neck cysts at the 13th gestational week. Both findings resolved spontaneously by the 18th gestational week, but during the third trimester this fetus developed hydrothorax, skin edema, and polyhydramnios. In the three other fetuses, first- and second-trimester ultrasonographic findings were normal, and the diagnosis of Noonan syndrome was suggested only during the third trimester. All three fetuses had polyhydramnios and skin edema. A cardiac malformation, hydrothorax, and a large head were present in one fetus. Sonographic facial findings were investigated. In all four fetuses posteriorly angulated, apparently low-set ears and depressed nasal bridge were identified. Wide nasal base was seen in two fetuses. In two fetuses, persistent opening of the fetal mouth was interpreted as fetal hypotonia. One fetus developed progressive postnatal hypertrophic cardiomyopathy and in one case, pulmonic stenosis became apparent at age 6 months. This small series suggests that Noonan syndrome has an evolving phenotype during in utero and postnatal life. Amelioration of early nuchal region findings and late onset of the more "typical" ultrasonographic changes may limit early prenatal detectability.

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.

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.