Finnish-type aspartylglucosaminuria detected by oligonucleotide ligation assay.

Aspartylglycosaminuria (AGU) is a recessively inherited lysosomal storage disease that occurs with much higher frequency in Finland than elsewhere. AGU is caused by a deficiency in glycosylasparaginase (GA), which results in the accumulation of glycoasparagines in lysosomes. In the Finnish population, a single nucleotide change in the gene encoding GA is responsible for the disease. We have used the oligonucleotide ligation assay (OLA) to detect the mutation in polymerase chain reaction (PCR)-amplified DNA samples from normal, carrier, and affected individuals. Screening for AGU among 415 random Finnish DNA samples with PCR/OLA revealed five carriers of the mutant allele and demonstrated the potential of the method for use in carrier screening. PCR/OLA provides a rapid, reliable, nonisotopic method to detect the mutation responsible for AGU that can readily be applied to large population screening.

The relationship between audiometric and self-report measures of hearing handicap.

In 430 individuals with adult onset hearing loss, relationships were explored between definitions of handicap based on a number of arithmetic formulas applied to audiometric data and definitions of handicap based on two self-report questionnaires (the Denver Scale of Communication Function and the Social Hearing Handicap Index). Resulting linear correlations were very low with the highest relationship--between better ear pure-tone average and perceived handicap--being only 0.38. Of the standard hearing handicap formulas, the 1947 American Medical Association calculation and the 1980 Ohio State formula showed the highest correlations with perceived handicap (0.33 and 0.28, respectively). The results highlight the difference between audiometrically calculated and self-reported hearing handicap.