Detecting Sex-Biased Gene Flow in African-Americans through the Analysis of Intra- and Inter-Population Variation at Mitochondrial DNA and Y- Chromosome Microsatellites.

This study reports on variations at the mitochondrial DNA (mtDNA) hypervariable region 1 (HVR-1) and at seven Y-chromosome microsatellites in an African-American population sample from Chicago, IL, USA. Our results support the hypothesis that the population studied had undergone a European male-biased gene flow. We show that comparisons of intra-and inter-population diversity parameters between African-Americans, Europeans and Africans may help detect sex-biased gene flow, providing a complement to quantitative methods to estimate genetic admixture.

Determinants of marital behaviour in five Apennine communities of Central Italy inferred by surname analysis, repeated pairs and kinship estimates.

The work makes use of surname analysis, repeated pairs and kinship estimates in 11,009 marriage records celebrated in five communities of the Italian Central Apennine (Celano, Lecce dei Marsi, Ortucchio, Roio, Villavallelonga) from 1802 to 1965 with the objective to deepen knowledge of the relative influence of several determinants on their marital behaviour. These towns are part of the same geographic and economic environment: the slopes of the ancient Fucino Lake. This work further elaborates the results from previous studies on the bio-demographic model of the region. The data were analyzed according to three periods of approximately 50 years. Results show the highest inbreeding coefficients in the pastoral towns of Roio and Villavallelonga. Repeated pair analysis highlights a certain degree of population subdivision which declined in time in Celano, Lecce dei Marsi and Ortucchio. The highest and increasing values of RP-RPr in time in Roio suggest a general reduction in genetic heterogeneity. This is possibly due to the celebration of marriages among families selected on the economic basis of pastoralism, as this town historically has had a leading tradition of sheep-farming. Villavallelonga, excluding isonymous marriages, shows an increase in repeated pair unions in time, thus revealing a substructure with marriages among preferred lineages. This is in line with previous results on consanguineous marriages which indicated the tendency of avoiding unions between close relatives in this small geographic isolate. This study demonstrates the influence of geographical (altitude) and social factors (pastoralism) on the marital structures of the investigated populations.

Familial spasmodic dysphonia with low arylsulphatase A (ASA) level.

Two familial cases of late onset spasmodic dysphonia and low Arylsulphatase A (ASA) are reported. In one case spasmodic dysphonia was associated with negative head tremor and orthostatic tremor, both displayed postural tremor of the upper extremities. A familial predisposition for both focal dystonia and metabolic lysosomal impairment is suggested by similar observations.