Factor XI (PTA) Deficiency in an English-American Kindred

Abstract

Summary2 sisters of English-American descent had a mild bleeding syndrome due to marked deficiency (less than 1 % activity) of factor XI. This defect was transmitted in an autosomal recessive manner. Although factor XI deficiency was previously thought to occur largely, if not exclusively in Jews, extensive review of geneologic records and analysis of family names failed to disclose Jewish ancestry. These findings, together with the existence of several definite and presumed consanguineous English-American ancestors, the fact that family members had resided in a restricted geographic area for many generations, and analysis of English and Jewish immigration patterns lead to the conclusion that this defect is not likely to be of Jewish derivation. Should this mutation have occurred in the distant past it is conceivable that the gene pool for this defect is substantial, particularly in certain areas in New England.

A common ancestral mutation (C128X) occurring in 11 non‐Jewish families from the UK with factor XI deficiency

“…This mutation was previously described in one of these individuals [12]. A further family from the USA, whose clinical details and inheritance have been previously reported [13], was found in this study to have the same mutation. The aim of this study was to determine whether or not this mutation stems from common ancestry.…”

“…Two patients (1 and 11 in Table 4) were found to be homozygous for the C128X mutation, and two other patients with severe FXI deficiency were compound heterozygous; in these the second F11 gene mutation was a single base‐pair insertion in exon 4 in one patient (patient 3 in Table 4), and has yet to be determined in the other (patient 5 in Table 4). Patient 1 is homozygous with documented consanguinity [13]; it is not known for patient 11 whether there is consanguinity.…”

Contact Factors in Health and Disease

“…62 ' 74 The frequency of homozygotes in the Ashkenazi Jewish community of Israel was 0.1 to 0.3% and that for heterozygotes 5.5 to 11%. 120 Small numbers of Factor XI deficiency were also reported in persons with apparent non-Jewish ancestry, such as English American, 146 black American, 81 Indian, 139 Arabian, 2 Italian, 93 German, 93 Korean, 117 and Japanese. 69,117 Interestingly, more than 25 families with this disorder were detected in Japan.…”

Factor XI deficiency in an arab moslem family in Israel

“…Most of the cases reported were in ashkenazi jews (2). 4 suspected cases have been reported in bantus of south Africa (3) and 3 cases in persons of mixed northern-european descent (4), a case report from Japan (5), an English-American kindred (6) and a black family (7). In Israel, all cases of PTA deficiency reported until now were in jews of ashkenazi descent (8)(9)(10)(11).…”