Mini-STRs screening of 12 relatives of Hausa Origin in northern Nigeria

The forensic identification of closely related individuals  genetically has often been difficult probably due to strong phenotypic concordances. Short tandem repeats (STRs) have been used in kinship tracing, identifying missing person and skeletal remains, paternity testing and mass disasters victim identification. This research was performed to determine the efficiency of the miniSTRsD14S1434 and D9S1122 in differentiating between closely related persons in Nigeria. The sample consisted of twelve individuals who self-identify as relatives. DNA extracted from blood was amplified using primers for the two miniSTR loci and resolved subsequently on 4% Agarose gel. An initial denaturation for 3 min at 95°C with annealing temperature at 57.4°C and 30 cycles of PCR produced best results. Different alleles of the markers D9S1122 (9, 10, 12, 13, 14,15,16) and D14S1434 (13,15,17,19,20) were identified in the samples studied with a high degree of heterozygosity as seen in the computed estimates of 0.8000 and 0.6364 for the D9S1122 and D14S1434 loci respectively. The gel resolutions show a combined probability of exclusion of 0.94 for the population and 0.97 for siblings. These loci can therefore efficiently differentiate individuals and establish family relationship in the Hausa population and will be important for forensic identification of individuals in the population.Keywords: STRs; identification; Hausa; Nigeria; Allele

Screening in silico predicted remotely acting NF1gene regulatory elements for mutations in patients with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1), a neuroectodermal disorder, is caused by germline mutations in the NF1 gene. NF1 affects approximately 1/3,000 individuals worldwide, with about 50% of cases representing de novo mutations. Although the NF1 gene was identified in 1990, the underlying gene mutations still remain undetected in a small but obdurate minority of NF1 patients. We postulated that in these patients, hitherto undetected pathogenic mutations might occur in regulatory elements far upstream of the NF1 gene. In an attempt to identify such remotely acting regulatory elements, we reasoned that some of them might reside within DNA sequences that (1) have the potential to interact at distance with the NF1 gene and (2) lie within a histone H3K27ac-enriched region, a characteristic of active enhancers. Combining Hi-C data, obtained by means of the chromosome conformation capture technique, with data on the location and level of histone H3K27ac enrichment upstream of the NF1 gene, we predicted in silico the presence of two remotely acting regulatory regions, located, respectively, approximately 600 kb and approximately 42 kb upstream of the NF1 gene. These regions were then sequenced in 47 NF1 patients in whom no mutations had been found in either the NF1 or SPRED1 gene regions. Five patients were found to harbour DNA sequence variants in the distal H3K27ac-enriched region. Although these variants are of uncertain pathological significance and still remain to be functionally characterized, this approach promises to be of general utility for the detection of mutations underlying other inherited disorders that may be caused by mutations in remotely acting regulatory elements