Relative frequencies of inherited retinal dystrophies and optic neuropathies in Southern France: assessment of 21-year data management.
OBJECTIVE
Inherited retinal dystrophies (IRDs) and inherited optic neuropathies (IONs) are rare diseases defined by specific clinical and molecular features. The relative prevalence of these conditions was determined in Southern France.


METHODS
Patients recruited from a specialized outpatient clinic over a 21-year period underwent extensive clinical investigations and 107 genes were screened by polymerase chain reaction/sequencing.


RESULTS
There were 1957 IRD cases (1481 families) distributed in 70% of pigmentary retinopathy cases (56% non-syndromic, 14% syndromic), 20% maculopathies and 7% stationary conditions. Patients with retinitis pigmentosa were the most frequent (47%) followed by Usher syndrome (10.8%). Among non-syndromic pigmentary retinopathy patients, 84% had rod-cone dystrophy, 8% cone-rod dystrophy and 5% Leber congenital amaurosis. Macular dystrophies were encountered in 398 cases (30% had Stargardt disease and 11% had Best disease). There were 184 ION cases (127 families) distributed in 51% with dominant optic neuropathies, 33% with recessive/sporadic forms and 16% with Leber hereditary optic neuropathy. Positive molecular results were obtained in 417/609 families with IRDs (68.5%) and in 27/58 with IONs (46.5%). The sequencing of 5 genes (ABCA4, USH2A, MYO7A, RPGR and PRPH2) provided a positive molecular result in 48% of 417 families with IRDs. Except for autosomal retinitis pigmentosa, in which less than half the families had positive molecular results, about 75% of families with other forms of retinal conditions had a positive molecular diagnosis.


CONCLUSIONS
Although gene discovery considerably improved molecular diagnosis in many subgroups of IRDs and IONs, retinitis pigmentosa, accounting for almost half of IRDs, remains only partly molecularly defined.
CHRU Montpellier, Genetics of Sensory Diseases, Montpellier, France.
Beatrice
B
Bocquet
Annie
A
Lacroux
Marie-Odile
MO
Surget
Corinne
C
Baudoin
Virginie
V
Marquette
Gael
G
Manes
Maxime
M
Hebrard
Audrey
A
Sénéchal
Cecile
C
Delettre
Anne-Francoise
AF
Roux
Mireille
M
Claustres
Claire-Marie
CM
Dhaenens
Jean-Michel
JM
Rozet
Isabelle
I
Perrault
Jean-Paul
JP
Bonnefont
Josseline
J
Kaplan
Helene
H
Dollfus
Patrizia
P
Amati-Bonneau
Dominique
D
Bonneau
Pascal
P
Reynier
Isabelle
I
Audo
Christina
C
Zeitz
José Alain
JA
Sahel
Veronique
V
Paquis-Flucklinger
Patrick
P
Calvas
Benoit
B
Arveiler
Suzanne
S
Kohl
Bernd
B
Wissinger
Catherine
C
Blanchet
Isabelle
I
Meunier
Christian P
CP
Hamel
D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins / Q000235:genetics; D015785:Eye Diseases, Hereditary / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007381:Intermediate Filament Proteins / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D009154:Mutation; D000081412:Myosin VIIa; D009218:Myosins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D064531:Peripherins; D016133:Polymerase Chain Reaction; D058499:Retinal Dystrophies / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D055815:Young Adult
C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D007381:Intermediate Filament Proteins; C000631455:MYO7A protein, human; D008562:Membrane Glycoproteins; D000081412:Myosin VIIa; D009419:Nerve Tissue Proteins; C578997:PRPH2 protein, human; D064531:Peripherins; C099929:RPGR protein, human; C112735:USH2A protein, human; D009218:Myosins