Genetic study of Welsh gypsies

Consanguineous marriages among Andalusian Gitanos/Calé: a genealogical analysis (1925-2006)

Using data from the family and genealogical reconstitutions of the Gitano population of 22 contiguous localities in eastern Andalusia, Spain, this study analysed the intensity, structure and historical evolution of consanguinity in 3056 couples formed from 1925 to 2006. Of these unions, 54.8% were consanguineous, and 28.7% involved relatives up to and including second cousins, resulting in a mean coefficient of inbreeding up to the third degree α3 = 12.4 × 10-3. The rest of the consanguineous unions (26.1% of all) involved more-distant relatives, such as third cousins, fourth cousins and so forth. When all consanguinity degrees found in the genealogical reconstitution were considered, the total mean coefficient of inbreeding was αt = 14.8 × 10-3. The merging of families and pedigrees generated a complex genealogical network with many inbreeding loops and important founder effects. This network revealed a high rate (62%) of Multiple Consanguineous Marriages (MCMs) in which second and subsequent consanguineous ties increased inbreeding levels by a fifth (20.5%). The accumulation of multiple degrees of distant relatedness, many of which had little social or biological importance, has contributed to a significant increase in inbreeding rates. Among Gitano people, intra-family marriages have remained common in the last decades, in sharp contrast to other Spanish populations. Hence the highest rates of close consanguinity (34%) and inbreeding (α3 = 14.6 × 10-3) were found in the 1960s, the decade that saw the onset of Spain's socioeconomic modernization, internationalization and massive migration. These are among the highest rates of inbreeding found in any European population, including the most endogamous Spanish isolates. They reveal marriage strategies not constrained primarily by geographical barriers, but by ethnocultural separation. Interestingly, in recent decades mixed marriages have been increasing rapidly in this minority, although they are compatible with high rates of consanguinity. Gitano secular endogamy is breaking up, but not uniformly.

Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma

Primary congenital glaucoma (PCG) is an autosomal recessive eye disease that occurs at an unusually high frequency in the ethnic isolate of Roms (Gypsies) in Slovakia. Recently, we linked the disease in this population to the GLC3A locus on 2p21. At this locus, mutations in the cytochrome P4501B1 (CYP1B1) gene have been identified as a molecular basis for this condition. Here, we report the results of CYP1B1 mutation screening of 43 PCG patients from 26 Slovak Rom families. A homozygous G-->A transition at nucleotide 1505 in the highly conserved region of exon 3 was detected in all families. This mutation results in the E387K substitution, which affects the conserved K helix region of the cytochrome P450 molecule. Determination of the CYP1B1 polymorphic background showed a common DNA haplotype in all patients, thus indicating that the E387K mutation in Roms has originated from a single ancestral mutational event. The Slovak Roms represent the first population in which PCG is found to result from a single mutation in the CYP1B1 gene, so that a founder effect is the most plausible explanation of its increased incidence. An ARMS-PCR assay has been developed for fast detection of this mutation, thus allowing direct DNA based prenatal diagnosis as well as gene carrier detection in this particular population. Screening of 158 healthy Roms identified 17 (10.8%) mutation carriers, indicating that the frequency of PCG in this population may be even higher than originally estimated.

Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma

Primary congenital glaucoma (PCG) is an autosomal recessive eye disease that occurs at an unusually high frequency in the ethnic isolate of Roms (Gypsies) in Slovakia. Recently, we linked the disease in this population to the GLC3A locus on 2p21. At this locus, mutations in the cytochrome P4501B1 (CYP1B1) gene have been identified as a molecular basis for this condition. Here, we report the results of CYP1B1 mutation screening of 43 PCG patients from 26 Slovak Rom families. A homozygous G→A transition at nucleotide 1505 in the highly conserved region of exon 3 was detected in all families. This mutation results in the E387K substitution, which affects the conserved K helix region of the cytochrome P450 molecule. Determination of the CYP1B1 polymorphic background showed a common DNA haplotype in all patients, thus indicating that the E387K mutation in Roms has originated from a single ancestral mutational event. The Slovak Roms represent the first population in which PCG is found to result from a single mutation in the CYP1B1 gene, so that a founder effect is the most plausible explanation of its increased incidence. An ARMS-PCR assay has been developed for fast detection of this mutation, thus allowing direct DNA based prenatal diagnosis as well as gene carrier detection in this particular population. Screening of 158 healthy Roms identified 17 (10.8%) mutation carriers, indicating that the frequency of PCG in this population may be even higher than originally estimated.

Estimating inbreeding from the Faculty Office Registers, 1534-1540

Estimates of inbreeding are rather scarce for British populations. A number of studies, especially of Scottish island populations, have focused on pedigree analysis, whilst others have used survey methods or inference from isonymy. By comparison with continental Europe, however, little is known of the historical development of inbreeding. This is undoubtedly due to the lack of evidence from dispensations to marry blood relatives, which are routinely available in the records of marriage of the Roman Catholic church. The paper uses as its data source the Faculty Office Registers, 1534-1540, which were the product of a new system of issuing dispensations following the Dispensations Act of 1533, and which are among the earliest administrative records of the Church of England, founded as a result of Henry VIII's breach with Rome. Dispensations are recorded in the Faculty Office until 1540, when all prohibitions on marriage beyond the proscribed relationships laid down in Leviticus were lifted. The data suggest surprisingly low levels of consanguineous marriage, including a lack of first-cousin marriages. These findings are discussed in terms of the reliability of the archive, and of the social and religious views attending marriage between blood relatives in the medieval and early modern periods.

Prevalence of congenital anomaly syndromes in a Spanish gypsy population

We analysed the sample of gypsies included in the Spanish Collaborative Study of Congenital Malformations (ECEMC), a hospital based, case-control study and surveillance system. Special emphasis was placed on the birth prevalence of recessive multiple congenital anomaly syndromes, comparing their frequency in the gypsy population with that observed among non-gypsies. We observed an increased prevalence of birth defects, mostly because of groups of children with patterns of multiple anomalies and with autosomal recessive syndromes. The latter were approximately seven times more frequent in gypsies than in non-gypsies. We also estimated the carrier frequency in both groups (gypsy and non-gypsy). We consider that the frequent occurrence of the conditions observed reflects the high rate of consanguineous couples among the Spanish gypsy population.

Traveller gypsies and primary care

Traveller gypsies have resided in the British Isles for over 500 years, making them one of our oldest ethnic minorities. They experience widespread prejudice and discrimination from the settled population. In the sphere of health care the marginalization of traveller gypsies has resulted in poor access to services and relative neglect of their health needs. In this paper the health of traveller gypsies is reviewed from the perspective of primary care, and the role of general practitioners in improving health care for this community is discussed.

Identification of the haplotype pattern associated with the mutant PKU allele in the Gypsy population of Wales

Using the full length cDNA probe, the RFLP haplotype patterns at the phenylalanine hydroxylase locus have been studied in the extensive and highly consanguineous Welsh Gypsy population. The pattern associated with the mutant PKU allele is identical to haplotype 4 in the northern European population. Two children with classical PKU are homozygous for this haplotype. We have tracked the mutant allele through four generations to a great grandfather who died 22 years ago. Both affected children almost certainly have inherited a double dose of the same mutant PKU allele from one common ancestor. It should be possible to identify the specific mutation that is associated with haplotype 4 which results in the more serious form of PKU.

Disease, lifestyle, and consanguinity in 58 American Gypsies

Medical data on 58 Gypsies in the area of Boston, Massachusetts, were analysed together with a pedigree linking 39 of them in a large extended kindred. Hypertension was found in 73%, diabetes in 46%, hypertriglyceridaemia in 80%, hypercholesterolaemia in 67%, occlusive vascular disease in 39%, and chronic renal insufficiency in 20%. 86% smoked cigarettes and 84% were obese. Thirteen of twenty-one marriages were consanguineous, yielding an inbreeding coefficient of 0.017. The analysis suggests that both heredity and environment influence the striking pattern of vascular disease in American Gypsies.

Genetic structure of the Greek gypsies

Data are presented on several polymorphic genetic markers in 200 Greek gypsies. Polymorphic loci studied were: the ABO, MN, Rhesus, Kell and Duffy blood groups, hemoglobin, and ceruloplasmin. A survey for congenital malformations and hereditary diseases was also carried out on this group. The ABO, Rhesus, MN and Duffy system frequencies varied significantly from the figures obtained for the Greek population. However, there is a characteristic similarity between various gypsy groups studied in other nations and the distribution of polymorphic traits in the Punjab region of India. Cystic fibrosis, renal tubular acidosis, 21-hydroxylase deficiency, Hoty-Oram syndrome and homozygous beta-thalassemia were diagnosed within the gypsy group studied.