Could the 185delAG BRCA1 mutation be an ancient Jewish mutation?

A predominant mutation within the BRCA1 predisposition gene, 185delAG, has been detected in about 1% of the Ashkenazi population, considered a high-risk group for breast and ovarian cancers. We examined 639 unrelated healthy Jews of Iraqi extraction, a presumed low-risk group, for the existence of this mutation. Three individuals were identified as 185delAG mutation carriers, and haplotype analysis of the Iraqi mutation carriers revealed that 2 of the Iraqis shared a common haplotype with 6 Ashkenazi mutation carriers, and 1 had a haplotype which differed by a single marker. This study suggests that the BRCA1 185delAG mutation also occurs in populations considered at low-risk for breast and ovarian cancers, and that it might have occurred prior to the dispersion of the Jewish people in the Diaspora, at least at the time of Christ.

The two common mutations causing factor XI deficiency in Jews stem from distinct founders: one of ancient Middle Eastern origin and another of more recent European origin

Previous studies showed that factor XI (FXI) deficiency commonly observed in Ashkenazi Jews is caused by two similarly frequent mutations, type II (Glu117stop) and type III (Phe283Leu) with allele frequencies of 0.0217 and 0.0254, respectively. In Iraqi Jews, who represent the ancient gene pool of Jews, only the type II mutation was observed with an allele frequency of 0.0167. In this study we sought founder effects for each mutation by examination of four FXI gene polymorphisms enabling haplotype analysis in affected Jewish patients of Ashkenazi, Iraqi, and other origins and in Arab patients. Initial population surveys of 387 Middle Eastern Jews (excluding Iraqi Jews), 560 North African/Sephardic Jews, and 382 Arabs revealed allele frequencies for the type II mutation of 0.0026, 0.0027, and 0.0065, respectively. In contrast, the type III mutation was not detected in any of these populations. All 60 independent chromosomes bearing the type III mutation were solely observed in Ashkenazi Jewish patients and were characterized by a relatively rare haplotype. All 103 independent chromosomes bearing the type II mutation in patients of Ashkenazi, Iraqi, Yemenite, Syrian, and Moroccan Jewish origin and of Arab origin were characterized by another distinct haplotype that was rare among normal Ashkenazi Jewish, Iraqi Jewish, and Arab chromosomes. These findings constitute the first example of a mutation common to Ashkenazi Jews, non-Ashkenazi Jews, and Arabs and are consistent with the origin of type II mutation in a founder before the divergence of the major segments of Jews. Our findings also indicate that the type III mutation arose more recently in an Ashkenazi Jewish individual.

Purpura fulminans induced by disseminated intravascular coagulation following infection in 2 unrelated children with double heterozygosity for factor V Leiden and protein S deficiency

Purpura fulminans is associated with homozygous protein C and homozygous protein S deficiency or may follow bacterial or viral infections. We present 2 children from 2 unrelated Arab families with purpura fulminans who were double heterozygotes for factor V Leiden inherited from their fathers and protein S deficiency inherited from their mothers. No previous thrombotic events have occurred in either patient or their respective family members. In one patient sepsis accompanied by disseminated intravascular coagulation appeared to be the trigger of purpura fulminans. In the other patient varicella infection preceded purpura fulminans and was also associated with disseminated intravascular coagulation. This report emphasizes the need for evaluation of hereditary defects in the inhibitory mechanisms of blood coagulation in patients with purpura fulminans at any age.

Factor XIII deficiency due to a Leu660Pro mutation in the factor XIII subunit-a gene in three unrelated Palestinian Arab families

In this report we describe the molecular basis of FXIII a-subunit deficiency in three unrelated Palestinian Arab families. In three patients representing each family two substitutions were identified in exon 14 on both alleles: C to G change resulting in a Gln651Glu substitution (a previously described polymorphism) and a T to C transition causing Leu660Pro substitution. The latter is a new mutation which creates a restriction site for FnuDII enzyme. Restriction analysis performed in members of the three families clearly distinguished between severely affected patients, obligate carriers and unaffected subjects. A population survey failed to detect the mutation among 250 Jewish individuals but did detect two heterozygotes among 300 Arabs suggesting a 0.0033 frequency for the Pro660 allele in this population. In two out of the three families the Pro660 allele was linked to allele 5 of the 5' short tandem repeat polymorphism within the FXIII a-subunit gene suggesting that the mutation might have occurred at least twice. cDNA obtained from mRNA isolated from patients' platelets and monocytes appeared similar in size to that of normal control indicating that the Leu660Pro mutation does not affect mRNA synthesis. Computer modeling based on cristallographic studies of the a-subunit of factor XIII predicted that the mutant protein is expected to misfold into a structure which is either unstable or susceptible to degradation.

Glanzmann thrombasthenia caused by an 11.2-kb deletion in the glycoprotein IIIa (beta3) is a second mutation in Iraqi Jews that stemmed from a distinct founder

Glanzmann thrombasthenia (GT) is a rare bleeding disorder resulting from mutations in either glycoprotein (GP) IIb or GPIIIa genes. The disease is relatively frequent in highly inbred populations such as Iraqi Jews. The molecular basis of GT in 6 unrelated Iraqi-Jewish patients was previously identified as an 11-bp deletion in exon 12 of the GPIIIa gene. We now describe a second mutation found in 3 unrelated Iraqi-Jewish families that consists of an 11.2-kb deletion between an Alu repeat in intron 9 and exon 13 of the GPIIIa gene. The mutant DNA is transcribed into mRNA in which exons 10 through 13 are absent. Splicing of exon 9 directly to exon 14 leads to a shift in the reading frame resulting in a stop codon. The predicted protein is truncated in the middle of the third cysteine-rich domain before the transmembrane domain. Simple DNA-based methods were devised for identification of both mutations in Iraqi Jews for the purpose of carrier detection and prenatal diagnosis enabling prevention of GT. A survey of the general Iraqi-Jewish population for the first 11-bp deletion and the second 11.2-kb deletion disclosed that the allele frequency of the first mutation was 0.0043, whereas none of 700 individuals examined bore the second mutation (allele frequency <0.0007). Among 40 GT patients of Iraqi-Jewish origin 31 were homozygous for the first mutation, 4 were compound heterozygotes for the first and second mutations, and 2 were homozygous for the second mutation. Haplotype analyses using 4 polymorphic markers in the GPIIIa gene showed that each mutation originated in a distinct founder.

Linkage of combined factors V and VIII deficiency to chromosome 18q by homozygosity mapping

Combined Factors V and VIII deficiency is an autosomal recessive bleeding disorder identified in at least 58 families comprising a number of different ethnic groups. Affected patients present with a moderate bleeding tendency and have Factor V and Factor VIII levels in the range of 5-30% of normal. The highest frequency of the mutant gene is found in Jews of Sephardic and Middle Eastern origin living in Israel with an estimated disease frequency of 1:100,000. We sought to identify the gene responsible for combined Factors V and VIII deficiency using a positional cloning approach. Of 14 affected individuals from 8 unrelated Jewish families, 12 were the offspring of first-cousin marriages. After a genome-wide search using 241 highly polymorphic short tandem repeat (STR) markers, 13 of the 14 affected patients were homozygous for two closely linked 18q markers. Patients and all available family members were genotyped for 11 additional STRs spanning approximately 11 cM on the long arm of chromosome 18. Multipoint linkage analysis yielded a maximal log of the odds (LOD) score of 13.22. Haplotype analysis identified a number of recombinant individuals and established a minimum candidate interval of 2.5 cM for the gene responsible for combined Factors V and VIII deficiency. The product of this locus is likely to operate at a common step in the biosynthetic pathway for these two functionally and structurally homologous coagulation proteins. Identification of this gene should provide new insight into the biology of Factor V and Factor VIII production.

A single genetic origin for a common Caucasian risk factor for venous thrombosis

A common genetic risk factor for venous thrombosis among Caucasoid subpopulations is a polymorphism, nt G1691A, in blood coagulation factor V that replaces Arg506 with Gln and imparts resistance of factor Va to the anticoagulant, activated protein C. Haplotype analyses using six dimorphic sites in the factor V gene for 117 Caucasian subjects of Jewish, Arab, Austrian, and French origin who were homozygous for nt A1691 compared with 167 controls (nt G1691) support a single origin for this polymorphism. The nt G1691A mutation is estimated to have arisen circa 21,000 to 34,000 years ago, ie, after the evolutionary divergence of Africans from non-Africans and of Caucasoid from Mongoloid subpopulations.

Acquired von Willebrand disease in a patient with angiodysplasia resulting from immune-mediated clearance of von Willebrand factor

A patient with a severe bleeding tendency due to acquired von Willebrand disease (VWD) is presented. Although no underlying disorder has emerged during 6 years of follow-up, an immune-mediated mechanism was responsible for acquired VWD in this patient as demonstrated by detection of von Willebrand factor (VWF)/anti-VWF complexes in the patient's plasma and their removal by protein A-sepharose beads and resumption of normal haemostasis with correction of VWF antigen, VWF activity and VWF multimeric pattern after treatment of the patient with high-dose gammaglobulin. Detection of anti-VWF antibodies in the patient's plasma had a significant impact on the choice of therapeutic intervention to control bleeding.

ETRO Working Party on Factor XIII questionnaire on congenital factor XIII deficiency in Europe: status and perspectives. Study Group

A questionnaire was sent out in 1993 to more than 350 European institutions caring for patients with hemorrhagic disorders with the request to provide data of patients with congenital factor XIII deficiency, to pursue the following aims: (1) establish a registry of congenital factor XIII deficiency patients, (2) promote exchange between clinicians and basic researchers, (3) improve diagnostic and therapeutic approaches, and (4) stimulate research on gene defects and their impact on factor XIII function. So far, 72 patient questionnaires from 60 families have been collected. Their bleeding pattern is typical, with frequent involvement of the umbilical cord and the central nervous system. Forty-nine patients receive regular factor XIII replacement, but obviously some patients with mild symptoms do not require prophylactic substitution, despite low factor XIII levels. On the other hand, 18 patients had factor XIII activities of > or = 5% of normal, but only 3 of those patients were reported to have no bleeding symptoms. Furthermore, 17 symptomatic, apparently heterozygous relatives in eight families were observed. Seven out of 30 females aged over 18 years had experienced spontaneous abortions; wound healing problems were seen in 26 patients. Currently, a second questionnaire is being distributed to obtain more detailed information on bleeding and other symptoms, diagnostic approaches, and exclusion of concurrent other bleeding diatheses. Future activities will be validation and standardization of assays, and study of gene defects and their impact on the structure of factor XIII and symptoms of patients. We intend to expand the survey to countries outside Europe.

Ala244Val is a common, probably ancient mutation causing factor VII deficiency in Moroccan and Iranian Jews

We investigated the molecular basis for factor VII (FVII) deficiency in Israel and found that 13 patients were homozygous and 10 heterozygous for a C to T substitution at nucleotide 10648 of the FVII gene. This predicted an Ala244Val change and was associated with decreased FVII activity and antigen level. Of the 36 Ala244Val positive alleles, 20 were observed in patients of Moroccan origin, 10 in Iranian-Jewish patients and 6 in patients of other origins. A computer model of the serine protease domain of FVII suggested that the Ala244Val substitution may cause distortion of the entire protein structure. Intragenic polymorphic sites analyses disclosed a founder effect for the Moroccan and Iranian-Jewish patients. A survey of the Ala244Val mutation revealed an allele frequency of 1:42.5 in Moroccan Jews and 1:40 in Iranian Jews. As Moroccan Jews have been separated from Iranian Jews for more than two millennia, the data suggest that the Ala244Val mutation occurred in ancient times.

Cyclosporine therapy for acquired factor VIII inhibitor in a patient with systemic lupus erythematosus

The case of a 27-year-old woman with systemic lupus erythematosus and development of an autoantibody against factor VIII during an exacerbation of her underlying disorder is described. Attempts to eliminate the antibody with high dose gammaglobulin and repeated courses of cyclophosphamide failed, whereafter she received cyclosporine in increasing doses. When therapeutic serum levels of cyclosporine were achieved (150-350 ng/ml) the inhibitor rapidly decreased and disappeared with a concomitant normalization of the factor VIII levels. Treatment with cyclosporine was subsequently reduced and discontinued after one year, and at present no inhibitor is detectable. In view of the successful results with cyclosporine treatment in 4 of 6 previous cases and in all 3 previous cases with autoimmune disorders, this regimen should be evaluated in a systematic manner as a potential first line drug in patients with acquired hemophilia and an underlying autoimmune disorder.

Venous thromboembolism associated with double heterozygosity for R506Q mutation of factor V and for T298M mutation of protein C in a large family of a previously described homozygous protein C-deficient newborn with massive thrombosis

It is remarkable that certain patients with heterozygous protein C (PC) deficiency manifest venous thromboembolism (VTE), whereas others, particularly those belonging to families with homozygous PC deficiency, remain asymptomatic. The goals of the present study of a family, in which the proband had homozygous PC deficiency, were to identify members with and without VTE, to determine the mutation causing PC deficiency, and to search for the R506Q mutation of factor V (FV) causing activated PC resistance. Heterozygosity for a T298M mutation in exon 9 of the PC gene was found in the father of the homozygous proband who died of massive thrombosis. Based on analysis of a three-dimensional molecular model of PC, we speculate that this mutation causes type I deficiency due to disruption of packing of hydrophobic side chains and loss of an H-bond between Q184 and T298. Forty-six family members were examined for the T298M mutation by polymerase chain reaction (PCR) amplification of exon 9 and restriction analysis using Mae III and for the FV R506Q mutation by PCR amplification of exon 10 and restriction analysis using Mnl I. VTE was observed in five of 11 members who were heterozygous for both PC and FV mutations. In contrast, VTE was not observed for the PC mutation in 13 heterozygotes who had normal FV, including the parents of the deceased proband, 10 heterozygotes for the FV mutation who had normal PC, and 12 individuals bearing neither mutation. These observations extend recent evidence of an increased thrombotic risk conferred by the coexistence of heterozygous PC deficiency and heterozygous activated PC resistance and support the paradigm in which hereditary thrombophilia is often a multigenic disease.

Coexistence of hereditary homocystinuria and factor V Leiden--effect on thrombosis

BACKGROUND

Venous and arterial thromboembolism occurs in only about one third of patients homozygous for homocystinuria, which suggests that other, contributory factors are necessary for the development of thrombosis in these patients. Factor V Leiden, an R506Q mutation in the gene coding for factor V, is the most common cause of familial thrombosis and could be a potentiating factor.

METHODS

We determined activated partial-thromboplastin times in the presence and absence of activated protein C and tested for the factor V Leiden mutation in 45 members of seven unrelated consanguineous kindreds in which at least 1 member was homozygous for homocystinuria.

RESULT

Thrombosis (venous, arterial, or both) occurred in 6 of 11 patients with homocystinuria (age, 0.2 to 8 years). All six also had the factor V Leiden mutation. One patient with prenatally diagnosed homocystinuria who was also heterozygous for factor V Leiden has received warfarin therapy since birth and has not had thrombosis (age, 18 months). Of four patients with homocystinuria who did not have factor V Leiden, none had thrombosis (ages at this writing, 1 to 17 years). Three women who were heterozygous for both homocystinuria and factor V Leiden had recurrent fetal loss and placental infarctions.

CONCLUSIONS

Patients with concurrent homocystinuria and factor V Leiden can have an increased risk of thrombosis. Screening for factor V Leiden may be indicated in patient with homocystinuria and their family members.

Carrier frequency of the IVS4 + 4 A-->T mutation of the Fanconi anemia gene FAC in the Ashkenazi Jewish population

Fanconi anemia (FA) is a genetically and phenotypically heterogeneous autosomal recessive disorder defined by a cellular hypersensitivity to DNA cross-linking agents. One of the FA genes, FAC, has been cloned and the genomic structure of the coding region has been characterized. We have developed amplification refractory mutation system (ARMS) assays for five known mutations in FAC, and have applied these assays to determine the carrier frequency of the IVS4 + 4 A-->T (IVS4) mutation in an Ashkenazi Jewish population. We tested 3,104 Jewish individuals, primarily of Ashkenazi descent, for the two most common FAC mutations, IVS4 and 322delG. Thirty-five IVS4 carriers were identified, for a carrier frequency of 1 in 89 (1.1%; 95% confidence interval 0.79% to 1.56%); no 322delG carriers were found. To determine if the IVS4 mutation was confined to the Ashkenazi Jewish population, we tested 563 Iraqi Jews for IVS4, and no carriers were found. Because the IVS4 mutation has only been found on chromosomes of Ashkenazi Jewish origin and is the only FAC mutation found on these chromosomes, we suggest that a founder effect is responsible for the high frequency of this mutation. With a carrier frequency greater than 1% and simple testing available, the IVS4 mutation merits inclusion in the battery of tests routinely provided to the Jewish population.

[International postgraduate training program in medicine: survey of 13 training courses, 1988-1994]

In 1988 an International Postgraduate Training Program in Medicine was established as a joint venture of the Tel Aviv University School of Continuing Medical Education and the Ministry for Foreign Affairs, Division of International Cooperation. During 1988-1994, 359 physicians participated. A survey of 271 graduates was carried out within 1-5 years following the completion of training, and 57% responded to our questionnaire. The program fulfilled the academic expectations of 78% of the trainees, and the practical clinical expectations of 80%. 95% graded the program as good-to-excellent from the sociocultural aspect. 75% and 67.5% of the trainees graded the program as good-to-excellent with regard to improvement in their theoretical and practical skills, respectively. Regretfully, only 45% have continued their ties with the host departments and only 11% have carried out joint research projects. These results imply that further attention should be paid to the trainees' real-time input, in order to increase satisfaction. Personal tutors should be nominated in each department, and should be adequately compensated. More emphasis should be given to initiation of bilateral research projects and maintenance of professional ties between the trainees and their host departments.

[Resistance to activated protein C--a novel cause of thrombophilia]

A point mutation in coagulation factor V which causes resistance to cleavage of factor Va by activated protein C (APC), was recently found to underlie thrombotic events. We examined 20 consecutive patients, under the age of 40, who suffered from idiopathic venous or arterial thrombosis. In 8 (40%) there was resistance to APC manifested by absence of the expected prolongation of activated partial thromboplastin time (aPTT). In 3, the addition of normal plasma corrected the anomaly in the patient's plasma, although the addition of factor V- deficient plasma caused no change. In a family of a 17-year-old boy with idiopathic deep venous thrombosis we found a mutation in factor V which was responsible for APC resistance. The patient and 4 family members showed a single G to A transition in position 1691 in their cDNA, resulting in substitution of arginine (506) for glutamine. The mutation in this area, which is the cleavage site for APC, is associated with thrombotic episodes and is frequently observed in patients with familial thrombophilia.

Glanzmann's thrombasthenia associated with deletion-insertion and alternative splicing in the glycoprotein IIb gene

Glanzmann's thrombasthenia is a bleeding disorder characterized by a decrease or absence of the functional platelet membrane glycoprotein (GP) complex, GPIIb/IIIa (alpha IIb beta 3). We describe a new deletion-insertion mutation in the GPIIb gene causing type I Glanzmann's thrombasthenia in two siblings of a consanguineous Iranian-Jewish family. The proband's platelets bound more antibodies against the vitronectin receptor-alpha V beta 3 than normal platelets, suggesting a normal GPIIIa (beta 3) gene and a defect in the GPIIb gene. Sequencing of amplified cDNA and genomic DNA fragments showed a 6-bp deletion and 31-bp insertion in exon 25 of the GPIIb gene. The predominant platelet GPIIb mRNA of the proband was a product of the splicing of exon 24 to a cryptic AG acceptor site in the insertion and encoded for deletion of amino acids Leu817-Asn826 and insertion of eight different amino acids. Cotransfection of COS-7 cells with expression vectors containing wild-type GPIIIa cDNA and the mutated GPIIb cDNA failed to produce detectable amounts of GPIIb/IIIa on the surface of the cells. Allele-specific restriction analysis of genomic DNA of family members showed homozygosity for the mutation in the affected siblings, heterozygosity in the parents, and homozygosity for the normal allele in an unaffected sibling. The observed mutation is in a region that is conserved from rodents to humans and has been suggested to be involved in the interaction between GPIIb and GPIIIa when these GPs are complexed in solution.

One of the two common mutations causing factor XI deficiency in Ashkenazi Jews (type II) is also prevalent in Iraqi Jews, who represent the ancient gene pool of Jews

In recent years four mutations causing factor XI deficiency have been identified in Jews of Ashkenazi (European) origin. Two of them, type II (a nonsense mutation) and type III (a missense mutation), were found to prevail among 125 unrelated Ashkenazi Jews with severe factor XI deficiency. A finding of type II mutation in four unrelated Iraqi-Jewish families raised the possibility that this mutation is also common in Iraqi Jews, who represent the ancient gene pool of the Jews. A molecular-based analysis performed in 1,040 consecutively hospitalized patients disclosed the following results: Among 531 Ashkenazi-Jewish patients, the type II allele frequency was 0.0217 and among 509 Iraqi-Jewish patients, 0.0167 (P = .50). The type III allele frequency in the Ashkenazi-Jewish patients was 0.0254, whereas none of 502 Iraqi-Jewish patients examined had this mutation. These data suggest that the type II mutation was present in Jews already 2.5 millenia ago. The data also indicate that the estimated risk for severe factor XI deficiency in Ashkenazi Jews (due to either genotype) is 0.22% and in Iraqi Jews, 0.03%, and that the estimated risk of heterozygosity in Ashkenazi Jews is 9.0% and in Iraqi Jews, 3.3%. As patients with severe factor XI deficiency are prone to bleeding after injury and patients with partial deficiency may have similar bleeding complications when an additional hemostatic derangement is present, the observed high frequencies should be borne in mind when surgery is planned for individuals belonging to these populations.