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D M Hoover

Publications and source records attributed to D M Hoover.

58 records · Page 4Linked to original sources

Phylogenetic analysis of mitochondrial DNA in Japanese pedigrees of sensorineural hearing loss associated with the A1555G mutation.

Thirteen Japanese families (ten of which were from the northern part of Japan), with sensorineural hearing loss associated with the 1555 A to G (A1555G) mitochondrial mutation, a known cause of non-syndromic hearing loss, were phylogenetically analysed using data obtained by restriction fragment length polymorphism (RFLP) and D-loop sequencing of mitochondrial DNA (mtDNA). Various types of mtDNA polymorphism were detected by restriction enzymes and D-loop sequence. No common polymorphic pattern throughout the 13 families was found, though three families exhibited the same restriction patterns and the same sequence substitution in the D-loop. To find where each of the 13 families are situated in the phylogenetic tree, the 482-bp of D-loop sequence were compared with those of 62 normal Japanese subjects. Despite the three families mentioned above appearing to be clustered, the remaining 10 families were scattered along the phylogenetic tree. This indicates that there was no common ancestor for the 13 Japanese families bearing the A1555G mutation except three families, and that the A1555G mutation occurred sporadically and multiplied through evolution of the mtDNA in Japan. The present results showed that the common pathogenicity (hearing loss associated with the A1555G mutation) can occur sporadically in families which have different genetic backgrounds, even in the Japanese population.

DNA, Mitochondrial↗

Reading disability and chromosome 6p21.3: evaluation of MOG as a candidate gene.

Linkage analysis has localized a gene influencing specific reading disability (dyslexia) to 6p21.3. The myelin oligodendrocyte glycoprotein (MOG) gene, which maps to this region, was selected as a candidate. Myelin oligodendrocyte glycoprotein is a membrane protein, a member of the immunoglobin superfamily, that is found on the outermost lamellae of mature myelin. Although the exact function of this protein is unknown, its presence in the central nervous system and the hypothesized relationship between dyslexia and temporal processing rate as well as a suggested relationship with intelligence made this gene a candidate for dyslexia. Analysis of the coding exons and adjacent splice sites in a subset of 22 children with dyslexia from 10 sibships found a missense mutation in exon 4 in 2 of the sibships. This change from the published sequence also occurred in 86 of 96 random controls, making it considerably less frequent in this small sample of individuals with dyslexia. Subsequent typing of this single nucleotide polymorphism (SNP) in 74 nuclear families in which at least one child had reading disability showed no significant difference in frequency from the controls, however. Sib-pair linkage analysis with these families did not show significant linkage with the SNP nor with a separate polymorphic dinucleotide repeat marker in the MOG gene (MOG31/32), but association analysis identified two alleles of MOG31/32 that were associated with reading disability phenotypes with a low level of significance. Thus, although alleles in the MOG gene may be in linkage disequilibrium with a locus that contributes to reading disability, it is unlikely that the MOG gene itself is involved.

Adolescent↗