[Propionic acidemia and sensorineural hearing loss: is there a connection at the molecular genetics level?].
BACKGROUND
Propionic acidemia is caused by a gene defect leading to malfunction of the enzyme propionyl-CoA carboxylase (PCC) and in turn to a pathologic accumulation of propionic acid. Many mutations have been found at the molecular genetic level over the past 20 years, and their implications for the limitation of enzyme activity of PCC in propionic acidemia are discussed.
As an elevated incidence of deafness has been observed in patients with propionic acidemia, the question arises of whether mutations primarily responsible for this disease could also be the underlying cause for a genetic form of deafness.


RESULTS
As well as a standard pure tone audiogram, a pedigree was elaborated and DNA isolated for each family concerned. In one family several subjects displayed mutations of both the PCCA and the PCCB -subunits; these included only one girl whose phenotype was affected, however.


CONCLUSIONS
Mutation of the PCCB subunit p.R113X has not previously been mentioned in the literature. According to our present knowledge no connection can be assumed between either of the two mutations and the severe sensorineural hearing loss.
Brosch
S
S
Sektion für Phoniatrie und Pädaudiologie der Universitäts- Hals-, Nasen-, Ohrenklinik, Schillerstr. 15, 89077, Ulm, Deutschland. sibylle.brosch@uniklinik-ulm.de
Rauffeisen
A
A
Baur
M
M
Michels
L
L
Trefz
F K
FK
Pfister
M
M
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006319:Hearing Loss, Sensorineural / Q000201:enzymology* / Q000235:genetics*; D006801:Humans; D008297:Male; D008661:Metabolism, Inborn Errors / Q000201:enzymology* / Q000235:genetics*; D043586:Methylmalonyl-CoA Decarboxylase / Q000235:genetics*; D010375:Pedigree; D011422:Propionates / Q000378:metabolism
D011422:Propionates; D043586:Methylmalonyl-CoA Decarboxylase; C029658:propionic acid