ABSTRACT
Statistical tests that detect and measure deviation from the Hardy-Weinberg equilibrium (HWE) have been devised but are limited when testing for deviation at multiallelic DNA loci is attempted. Here we present the full Bayesian significance test (FBST) for the HWE. This test depends neither on asymptotic results nor on the number of possible alleles for the particular locus being evaluated. The FBST is based on the computation of an evidence index in favor of the HWE hypothesis. A great deal of forensic inference based on DNA evidence assumes that the HWE is valid for the genetic loci being used. We applied the FBST to genotypes obtained at several multiallelic short tandem repeat loci during routine parentage testing; the locus Penta E exemplifies those clearly in HWE while others such as D10S1214 and D19S253 do not appear to show this.
Subject(s)
Alleles , Bayes Theorem , Models, Genetic , Polymorphism, Genetic/genetics , Linkage Disequilibrium/genetics , Gene Frequency/genetics , HumansABSTRACT
1. Five Brazilian families referred to us with a probable diagnosis of chronic proximal spinal muscular atrophy (Kugelberg-Welander) were identified, and permanent (Epstein Barr virus transformed) cell lines were established from members of four of the families. 2. A genetic linkage study was carried out on 70 individuals using nine polymorphic DNA markers (eight RFLP and one microsatellite) from chromosome 5q11.2-13.3 which have been shown to flank the spinal muscular atrophy (SMA) gene. 3. The segregation of the markers in two of the five families was compatible with the disease-causing locus being located in this same region. In one family the pattern of segregation clearly excludes the causative gene from this region. In one of the remaining two families the analysis was inconclusive because the markers were not informative. In the fifth family the possibility of two concurrent neuromuscular diseases did not permit a definite conclusion. 4. These results further support the location of the major SMA gene at 5q11.2-13.3. 5. The possibility of non-allelic heterogeneity for the spinal muscular atrophy gene is discussed