Prenatal diagnosis of a rhodopsin mutation using chemical cleavage of the mismatch.
OBJECTIVE
Mutations of the rhodopsin gene are responsible for autosomal dominant or recessive retinitis pigmentosa (RP). The present study reports the first prenatal diagnosis performed on chorionic villi biopsy of a pregnant woman affected by a severe form of autosomal dominant transmitted RP, due to the Arg135Trp substitution.


METHODS
The rhodopsin gene was analysed by automated direct sequencing and, for the first time, by fluorescence-assisted mismatch analysis (FAMA). The latter is an inexpensive, rapid and particularly sensitive method, based on the chemical cleavage of the mismatch in heteroduplex DNA molecules marked with strand-specific fluorophores.


RESULTS
FAMA is a feasible procedure for prenatal molecular diagnosis of rhodopsin mutations. The redundancy of signals obtained by FAMA and its sensitivity make it suitable for identifying exactly the position of the mutation and the nucleotide substitution.


CONCLUSIONS
An association is proposed between FAMA and automated direct sequencing procedures, in order to achieve optimal results in terms of reliability for prenatal diagnosis of rhodopsin mutations.
Tessitore
Alessandra
A
Department of Experimental Medicine, University of L'Aquila, Italy.
Toniato
Elena
E
Gulino
Alberto
A
Frati
Luigi
L
Ricevuto
Enrico
E
Vadalà
Maria
M
Vingolo
Enzo
E
Martinotti
Stefano
S
D000328:Adult; D020137:Base Pair Mismatch / Q000235:genetics*; D015193:Chorionic Villi Sampling; D004247:DNA / Q000032:analysis; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D020180:Heteroduplex Analysis / Q000379:methods*; D006801:Humans; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000235:genetics*; D012243:Rhodopsin / Q000235:genetics*
D004247:DNA; D012243:Rhodopsin