The nature of different phenotypes associated with the FMR1 mutation in its premutation and full mutation forms and the inheritance pattern are complex.
Unlike mtDNA mutations, the pattern of inheritance of MDS is autosomal recessive.
Our findings are consistent with both loss- and gain-of-function disorders among the PCP mutants, and suggest that the wide range of NTD-like phenotypes that are associated with human PCP mutations might be explained by the inheritance of different combinations of mutant alleles in different individuals.
In situations where a couple has the same mutation, analysis of single nucleotide polymorphism (SNP) can be used to trace the inheritance of mutations as the SNP can be with either of the alleles.
Presently, fewer than 10% of tumor cases are attributable to the inheritance of mutations in a single gene, such as BRCA1/2, BRAF and p53.
Although our studies do not detect a loss of catalytic function resulting from dystonia-parkinsonism mutations, the recessive pattern of inheritance suggests that they are more likely to cause a loss of function rather than a dominant gain of function.
In view of the growing concern about reduction of allelic polymorphism, possibly by natural selection [23], [24], [77] opposing the continuing expansion of genetic diversity, the inheritance of mutation loads to F1 and F2 progeny calls for a major conceptual change.
If a disease causing mutation was not found, and the inheritance pattern suggested a sporadic case or X-linked dominant disease, multiplex ligand-dependent probe amplification (MLPA) analysis of PHEX were performed at the Molecular Genetics Laboratory, Royal Devon and Exeter Foundation NHS Trust, Exeter, Devon, UK.
Our results highlight the complexity of the inheritance of adaptive mutations.
Excessive ambient noise, aging populations, exposure to ototoxic drugs, and the inheritance of genetic mutations are believed to contribute to the prevalence of hearing and balance disorders.
