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

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

Phenotypic expression of tissue mosaicism in a 45,X/46,X,dicY(q11.2) female

We describe a girl who presented at the age of 11 years with short stature. She had female external genitalia and some clinical features of Turner syndrome. At laparotomy a uterus and Fallopian tubes and small gonad-like tissue masses in the region of the Fallopian fimbria were found. The tissue masses were removed and histological examination revealed no organized testicular or ovarian morphology. Remnants of Fallopian tubes, epididymis, and clusters of Leydig cells were seen but no Sertoli cells were found. Endocrine studies showed levels of sex hormones consistent with primary gonadal failure. G-banding analysis of 16 blood lymphocytes revealed the karyotype 46,X,dicY(q11.2) in all cells. Varying proportions of X and Y centromeres in blood lymphocytes, skin fibroblasts, and in the incompletely formed Wolffian and Müllerian duct derivatives were demonstrated by FISH. Molecular studies confirmed the absence of most of the long arm of the Y chromosome and an intact short arm. The SRY gene was shown to be present, but we presume that due to the mosaicism the dose was insufficient to allow normal testicular development.

Cytokine profile of patients with mycosis fungoides and the immunomodulatory effect of AS101

Cytokines are known to play a major role in the pathogenesis of mycosis fungoides, a cutaneous malignant neoplasm of CD 4 T cells. In the present study, we investigated the effect of AS101, a tellurium-based compound with immunomodulating properties, on the pattern of lymphokine production by peripheral blood mononuclear cells (PBMCs) from patients with mycosis fungoides. PBMCs were isolated from 35 patients with mycosis fungoides stage IA and IB before initiation of treatment and from 20 healthy sex and age-matched controls. Unstimulated and phytohaemagglutinin-stimulated PBMCs were tested with and without the addition of AS101. The production of interferon-gamma, interleukin 2 (IL-2), IL-2 receptor (IL-2R), interleukin 5 (IL-5) and interleukin 10 (IL-10) was determined by enzyme-linked immunosorbent assays. The effects of AS-101 on mycosis fungoides PBMCs were compared to those of healthy donor PBMCs. Significantly higher levels of IL-2R, IL-5 and IL-10 and significantly lower levels of interferon-gamma were found in the patients compared to the controls. There was no significant difference between the groups in the production of IL-2. AS101 inhibited the production of IL-2R, IL-5 and IL-10 and induced a significant increase in IL-2 levels in the mycosis fungoides PBMCs. These findings may have important clinical implications for the possible therapeutic benefit of AS101 in mycosis fungoides.

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

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

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

BACKGROUND

Familial nephritis is a heterogeneous group of disorders caused by several genetic conditions such as Alport syndrome, glomerulonephritic syndromes, and unclassified nephritis without deafness or ocular defects.

OBJECTIVES

To describe a family of Iraqi Jewish origin, several of whose members suffer from non-syndromic renal failure without deafness or ocular defects and where transmission is by autosomal dominant inheritance. We present the case histories of four family members and describe the molecular analysis performed in order to seek a possible linkage to one of the genes causing Alport or Alport-like syndromes.

METHODS

We investigated all family members over the age of 18 for evidence of renal failure. We also extracted DNA and carried out molecular linkage analysis with polymorphic markers in each of the known loci involved in Alport and Alport-like syndromes.

RESULTS

Histology of the renal biopsy specimens showed non-specific findings. Linkage was excluded for all the Alport and Alport-like syndrome loci.

CONCLUSIONS

The condition suffered by several members of this family seems to represent a unique autosomal dominant type of progressive hereditary nephritis, characterized by hypertension and progressive renal failure without significant hematuria or proteinuria. The main histological changes are non-specific in the early stage of the disease. Our study rules out all the currently known genes that cause Alport syndrome as being responsible for the basic defect in this type of nephritis.

Ectodermal dysplasia, ectrodactyly and macular dystrophy (EEM syndrome) in siblings

We report a brother and sister with ectodermal dysplasia, ectrodactyly, and macular dystrophy (the EEM syndrome). Both children had abnormalities of the hands and the hair, and bilateral macular degeneration. The clinical picture in both is similar to, but less severe than, that described in the previously reported cases of this rare syndrome. Even though the parents are not related, they are both of Jewish Yemenite origin, and the possibility of a common ancestor cannot be ruled out. This would suggest autosomal recessive inheritance. The clinical picture in these patients suggests either variable expression or genetic heterogeneity in the EEM syndrome and further delineates the clinical and genetic spectrum of this condition.

Modifier locus for mitochondrial DNA disease: linkage and linkage disequilibrium mapping of a nuclear modifier gene for maternally inherited deafness

PURPOSE

To examine the role of the nuclear genome in affecting the phenotypic expression of the simplest model of a mitochondrial DNA disease, maternally transmitted deafness.

METHODS

Linkage analysis in families with maternally inherited deafness associated with the homoplasmic A1555G mutation.

RESULTS

Significant linkage and linkage disequilibrium on chromosome 8 was identified.

CONCLUSIONS

This finding represents the first identification of a modifier locus for a human mitochondrial DNA disease and supports the concept of mitochondrial DNA diseases having complex genetic inheritance. The eventual identification of this modifier gene will provide insights into the pathophysiological pathways determining the clinical expression of mitochondrial DNA diseases, an important step toward diagnostic and therapeutic interventions.

Novel approach to the molecular diagnosis of Marfan syndrome: application to sporadic cases and in prenatal diagnosis

Marfan syndrome is an autosomal dominant disorder affecting the skeletal, ocular, and cardiovascular systems. Defects in the gene that encodes fibrillin-1 (FBN1), the main structural component of the elastin-associated microfibrils, are responsible for the disorder. Molecular diagnosis in families with Marfan syndrome can be undertaken by using intragenic FBN1 gene markers to identify and track the disease allele. However, in sporadic cases, which constitute up to 30% of the total, DNA-based diagnosis cannot be performed using linked markers but rather requires the identification of the specific FBN1 gene mutation. Due to the size and complexity of the FBN1 gene, identification of a causative Marfan syndrome mutation is not a trivial undertaking. Herein, we describe a comprehensive approach to the molecular diagnosis of Marfan syndrome that relies on the direct analysis of the FBN1 gene at the cDNA level and detects both coding sequence mutations and those leading to exon-skipping, which are often missed by analysis at the genomic DNA level. The ability to consistently determine the specific FBN1 gene mutation responsible for a particular case of Marfan syndrome allows both prenatal and pre-implantation diagnosis, even in sporadic instances of the disease.

Triple-test screening in in vitro fertilization pregnancies

PURPOSE

To determine whether the results of triple-test analysis differ between spontaneous and IVF pregnancies.

METHODS

The study population consisted of 140 women with singleton pregnancies, 70 by IVF, and 70 by spontaneous conception. The groups were matched for maternal age, gestational week, and laboratory batch. The levels of all triple-test markers--alpha-fetoprotein (AFP), human chorionic gonadotropin (HCG), and unconjugated estriol (u-E3)--were compared between the groups.

RESULTS

Significantly higher HCG levels were detected in the patients with IVF pregnancies than in the control group (1.31 +/- 0.8 vs. 0.95 +/- 0.5 multiple of the medians, respectively, (p < 0.006), but there were no significant differences in AFP or u-E3 levels. Overall, 18.5% of the IVF group were found to be screen-positive as compared with 11.4% of the control group (difference not statistically significant). Only 8 IVF pregnancies (11.4%) reached the lowest calculated risk possible (1:9999) compared with 17 (24.2%) in the control group (p < 0.05).

CONCLUSIONS

Our findings support previous data demonstrating elevated maternal serum HCG in IVF patients in comparison with spontaneous ones.

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

OBJECTIVES

The angiotensin-converting enzyme (ACE) gene polymorphism has been associated with worse outcome in various chronic glomerular disorders and in hypertension. Because nephritis and vascular morbidity are prominent determinants of outcome in systemic lupus erythematosus (SLE), we studied the distribution and prognostic effect the ACE genotype might have on the outcome of SLE.

METHODS

Fifty-six consecutive Israeli SLE patients and 48 (sex and ethnic origin matched) healthy individuals were evaluated for the ACE genotype by a polymerase chain reaction-based assay. The clinical and laboratory parameters of the patients as well as the SLE disease activity index (SLEDAI) and the presence of hypertension, diabetes mellitus, ischemic heart disease, congestive heart failure, and stroke were correlated with the ACE genotype.

RESULTS

The distribution of the ACE genotype D/D, D/I, and I/I in the lupus group was 59%, 36%, and 5%, respectively, similar to the distribution in the control group (54%, 31%, and 15%, respectively). We failed to find any significant association between the ACE genotype and disease manifestations, SLEDAI, renal function, or cardiovascular and cerebrovascular morbidity. The clinical and laboratory parameters associated with renal outcome and vascular morbidity in our cohort are described.

CONCLUSIONS

No difference was found between the distribution of the ACE genotype in lupus patients and the general population in Israel. Renal function as well as cardiovascular and cerebrovascular morbidity among Israeli patients with SLE are disease-related and independent of the ACE gene polymorphism.

A locus for an autosomal dominant form of progressive renal failure and hypertension at chromosome 1q21

Linkage studies were performed in a large family with an autosomal dominant phenotype characterized by nephropathy and hypertension. In this family of Iraqi Jewish origin, the nephropathy develops into progressive renal failure. By performing a genomewide linkage search, we localized the disease gene to chromosome 1q21; the highest LOD score was obtained for the marker at locus D1S305, which yielded a maximum LOD score of 4.71 at a recombination fraction of 0. Recombination mapping defined an interval of approximately 11.6 cM, between the markers at loci D1S2696 and D1S2635, that contains the disease gene. Localization of the disease-causing gene in this family represents a necessary step toward isolation of the defective gene and toward a deeper understanding of the mechanisms of hypertension and progressive renal failure.

Achondroplasia in diverse Jewish and Arab populations in Israel: clinical and molecular characterization

BACKGROUND

Achondroplasia is the most frequent form of disproportionate short stature, characterized by rhizomelic shortening of the limbs. This disorder is inherited as an autosomal dominant trait, although most of the cases are sporadic, a result of a de novo mutation. A recurrent glycine to arginine mutation at codon 380 (G380R) in the transmembrane domain of the fibroblast growth factor receptor 3 gene was found to cause achondroplasia among different populations. This is most uncommon in other autosomal dominant genetic diseases.

OBJECTIVES

To determine whether this mutation is also common among Jewish patients from diverse ethnic groups and among the Arab population in Israel.

METHODS

We examined the G380R mutation (G > A and G > C transition) and the mutation G375C (G > T transition at codon 375) in 31 sporadic patients and in one family diagnosed clinically to have achondroplasia.

RESULTS

We found the G > A transition at codon 380 in 30 of our patients and the G > C transition in one patient. We were not able to detect any of the three mutations in two patients with an atypical form of achondroplasia.

CONCLUSIONS

Our results further support the unusual observation that nucleotide 1138 of the FGFR3 gene is the most mutable nucleotide discovered to date across different populations.

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

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

Multiple de novo MPZ (P0) point mutations in a sporadic Dejerine-Sottas case

Dejerine-Sottas syndrome (DSS), a severe demyelinating peripheral neuropathy with onset in infancy, has been associated with mutations in either PMP22 or MPZ. Most cases of DSS are caused by a single heterozygous dominant point mutation. We identified three de novo point mutations in MPZ exon 3 in a sporadic DSS patient. These three point mutations occur on the same allele and result in three novel amino acid substitutions: Ile(85)Thr, Asn(87)His, and Asp(99)Asn. Our data raise the question as to the potential mechanism(s) involved in the formation of multiple point mutations at a given locus.

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.

Assessment of pyrin gene mutations in Turks with familial Mediterranean fever (FMF)

Familial Mediterranean fever (FMF) is an autosomal recessive disease clinically characterized by recurrent short self-limited attacks of fever accompanied by peritonitis, pleurisy, and arthritis and can lead to amyloidosis and renal failure in the longer term. It is prevalent mainly in non-Ashkenazi Jews, Armenians, Turks, and Arabs. Due to the lack of an accurate diagnostic test, patients often experience years of attacks and invasive diagnostic procedures before the correct diagnosis is made and adequate treatment is begun. Recently, the gene responsible for FMF, denoted pyrin, has been cloned, and three disease mutations have been described (French FMF Consortium, 1997; International FMF Consortium, 1997). In the current study we assessed the spectrum of mutations in this gene in 16 unrelated families of Turkish origin. The three previously reported missense mutations (Met-Ile at codon 680, Met-Val at codon 694, and Val-Ala at codon 726) accounted for 29 of the 34 disease alleles. In one patient in whom no disease mutation was identified, the clinical picture was atypical enough to raise questions regarding the diagnosis. These results imply that the origin of FMF in Turkey is heterogeneous, that molecular diagnosis of FMF is possible in the majority of cases and clinically helpful, and that delineation of the undiscovered disease mutation(s) in the remaining cases remains a high priority.

Candidate locus for a nuclear modifier gene for maternally inherited deafness

Maternally inherited deafness associated with the A1555G mutation in the mitochondrial 12S ribosomal RNA (rRNA) gene appears to require additional environmental or genetic changes for phenotypic expression. Aminoglycosides have been identified as one such environmental factor. In one large Arab-Israeli pedigree with congenital hearing loss in some of the family members with the A1555G mutation and with no exposure to aminoglycosides, biochemical evidence has suggested the role of nuclear modifier gene(s), but a genomewide search has indicated the absence of a single major locus having such an effect. Thus it has been concluded that the penetrance of the mitochondrial mutation appears to depend on additive effects of several nuclear genes. We have now investigated 10 multiplex Spanish and Italian families with 35 members with the A1555G mutation and sensorineural deafness. Parametric analysis of a genomewide screen again failed to identify significant evidence for linkage to a single autosomal locus. However, nonparametric analysis supported the role of the chromosomal region around marker D8S277. The combined maximized allele-sharing LOD score of 3.1 in Arab-Israeli/Spanish/Italian families represents a highly suggestive linkage result. We suggest that this region should be considered a candidate for containing the first human nuclear modifier gene for a mitochondrial DNA disorder. The locus operates in Arab-Israeli, Spanish, and Italian families, resulting in the deafness phenotype on a background of the mitochondrial A1555G mutation. No obvious candidate genes are located in this region.

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

OBJECTIVE

The gene causing familial Mediterranean fever (FMF)-an autosomal recessive disease characterized by recurrent short episodes of fever associated most commonly with peritonitis, pleuritis, and arthritis-has recently been found and several mutations identified. The most severe complication of the disease is amyloidosis, which can lead to renal failure. The aim of this study was to investigate the role of genetic versus nongenetic factors on the phenotype as well as on the development of amyloidosis in FMF in a large and heterogeneous group of patients.

METHODOLOGY

We studied 382 patients from 4 ethnic origins living in different environments: North African Jews, other Jews, Turks, Armenians living in the United States, and Armenians from Yerevan, Armenia. Information regarding amyloidosis was available for 371 patients. We examined the association between the mutation M694V and the development of amyloidosis, and we also compared the clinical characteristics of the inflammatory attacks in patients from different ethnic origins, while controlling for the type of mutation.

RESULTS

A significant association was found between amyloidosis and the most common mutation in exon 10 of the FMF gene (MEFV), M694V (for M694V homozygotes, relative risk = 1.77; 95% CI = 1.16-2.71). Amyloidosis was present in 44 of 171 homozygous FMF patients (25.7%), in 22 of 143 compound heterozygous FMF patients (15.4%), and in 7 of 57 patients carrying other mutations (12.3%). In homozygotes for M694V who had not been treated with colchicine before 20 years of age, the risk of amyloidosis developing before this age was 61.0%. In our series, there were no cases of amyloidosis in 16 patients carrying the common mutation E148Q. We found that the type and severity of the FMF inflammatory symptoms were associated with both the genotype and the country of residence of the patient.

CONCLUSIONS

In the light of the high frequency of amyloidosis in homozygotes for the mutation M694V, colchicine treatment should be given to this group irrespective of the severity of the inflammatory attacks to prevent the development of amyloidosis. Our findings also suggest that factors other than genotype, such as environment or genes other than MEFV, play a role in the determination of the severity of the inflammatory attacks in FMF. amyloidosis, specific mutation, phenotype-genotype correlation, ethnicity.

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

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

Gender differences in the reactogenicity of measles-mumps-rubella vaccine

BACKGROUND

In trials comparing different formulations of measles vaccine, excess non-specific mortality occurred in female children who received high titer vaccine. These findings suggest a gender-specific effect of measles vaccine.

OBJECTIVES

To determine whether gender differences exist in the rates of adverse reactions and morbidity in the month following immunization with measles-containing vaccine, and to evaluate whether there is a gender-specific association between the humoral immune response to measles vaccination and post-vaccination morbidity.

METHODS

Parents completed questionnaires on the health status of 755 infants aged 15-20 months, during the month preceding and the month following the measles-mumps-rubella vaccination. Blood samples were tested for measles antibody titers in a subsample of 237 infants.

RESULTS

After controlling background morbidity in the infants, the relative risk of fever and rash following vaccination was 2.35 in females and 1.36 in males. The geometric mean antibody titers against measles were similar in both sexes and there was no significant association between antibody titer and post-vaccination morbidity in either sex.

CONCLUSIONS

Our findings demonstrate higher rates of adverse effects in females following vaccination with MMR vaccine, irrespective of the humoral response. This study emphasizes the need to consider possible gender differences when evaluating new vaccines.

Atopic dermatitis and HTLV-1-associated myelopathy: associated or coincidental disorders?

Reports from Jamaica have indicated that some patients with infective dermatitis or atopic dermatitis (AD) are seropositive for antibodies to human T-lymphotropic virus type 1 (HTLV-1). We describe a 32-year-old Israeli woman with long-term AD and paresthesia in the distal parts of the extremities. Neurological examination revealed a positive Babinski's sign. HLA typing demonstrated that this patient has the common HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and infective dermatitis haplotype for DRB1* DQB1*. The presence of HTLV-1 was demonstrated with polymerase chain reaction; HTLV-1-antibodies were detected by the Western blot method and by inoculation of the patient's peripheral blood mononuclear cells into F344 rats. This study confirms the presence of HTLV-1 antibodies and proviral genome in a patient with AD which later evolved into HAM/TSP. We cannot yet conclude whether these two diseases are associated or coincidental disorders.

Reaching the diagnosis of cystic fibrosis--the limits of the spectrum

BACKGROUND

Cystic fibrosis is the most common life-limiting autosomal recessive genetic disorder in Caucasians. Typically it is a multisystem disease diagnosed by increased chloride levels on sweat testing, with mortality due mainly to progressive respiratory disease. The clinical spectrum of CF has recently been much expanded. Genetic testing for mutant CF transmembrane regulator has revealed atypical cases where sweat test results are borderline or normal. In other patients, genetic mutations cannot be identified but abnormal CFTR function is shown using nasal potential difference measurement.

OBJECTIVES

To highlight the diagnostic and therapeutic dilemmas in cases of atypical cystic fibrosis.

METHODS

We reviewed patients with atypical CF and widely varying phenotype who are managed at Schneider Children's Medical Center of Israel.

RESULTS

Two patients had severe lung disease but little expression in other organs. Accurate diagnosis was essential to enable aggressive therapy in a specialized center. Four other patients are in excellent general health but have symptoms limited to male infertility, heat exhaustion, pancreatitis or transient liver dysfunction, while lung disease is minimal. For these patients, careful counseling is needed to avoid unnecessary upheaval, inappropriately aggressive management, and the psychosocial implications of a CF diagnosis. These dilemmas have increased considerably in our center, as in others worldwide.

CONCLUSION

It is our obligation as clinicians--at the level of both primary physician and referral center--to maintain an ever higher index of suspicion for CF, tempered by a rational program of counseling and management appropriate to the individual.

Blood pressure measurements in Israeli Arab children and adolescents

BACKGROUND

Hypertension is one of the most prevalent vascular diseases in the adult population. It is an important determinant of atherosclerosis in adolescents and young adults. There is to date no information on blood pressure in children of the Israeli Arab population.

OBJECTIVES

To study blood pressure in Israeli Arab children and adolescents.

METHODS

Blood pressure measurements were taken in the supine position in 4,488 Israeli Arab children and adolescents of both sexes aged 6-17 years. Height and weight were also determined. Correlation was investigated between systolic and diastolic blood pressure, body mass index, gender, and age.

RESULTS

The systolic and diastolic blood pressures were similar in both sexes for all age groups up to 14 years of age. Systolic blood pressure was significantly (P < 0.001) higher in males aged 15-17 years (120 +/- 13 vs. 111 +/- 12 mmHg, 123 +/- 13 vs. 113 +/- 14.0 mmHg, and 123 +/- 18 vs. 111 +/- 14 mmHg, respectively). Diastolic blood pressure was higher in males aged 15-17, with a statistically significant difference for age 17 only (75 +/- 12 vs. 69 +/- 13 mmHg). Blood pressure was elevated in 322 students in the initial screening (7.17%), with a decrease to 2.18% when this group was rescreened 2 weeks later. The systolic blood pressure in our group is higher than that in Jewish Israeli children of Asian and North African origin, and in American children. It is similar to the systolic blood pressure of European children and Jewish children born in Israel. The diastolic blood pressure in our group is higher than that in all groups of Israeli Jewish children and American children of different ethnic groups.

CONCLUSIONS

Israeli Arab children and adolescents have higher blood pressure levels than their Israeli Jewish counterparts. Further studies are required to confirm this observation.