The ADAMTS18 gene is responsible for autosomal recessive early onset severe retinal dystrophy.
BACKGROUND
Inherited retinal dystrophies, including Retinitis Pigmentosa and Leber Congenital Amaurosis among others, are a group of genetically heterogeneous disorders that lead to variable degrees of visual deficits. They can be caused by mutations in over 100 genes and there is evidence for the presence of as yet unidentified genes in a significant proportion of patients. We aimed at identifying a novel gene for an autosomal recessive form of early onset severe retinal dystrophy in a patient carrying no previously described mutations in known genes.


METHODS
An integrated strategy including homozygosity mapping and whole exome sequencing was used to identify the responsible mutation. Functional tests were performed in the medaka fish (Oryzias latipes) model organism to gain further insight into the pathogenic role of the ADAMTS18 gene in eye and central nervous system (CNS) dysfunction.


RESULTS
This study identified, in the analyzed patient, a homozygous missense mutation in the ADAMTS18 gene, which was recently linked to Knobloch syndrome, a rare developmental disorder that affects the eye and the occipital skull. In vivo gene knockdown performed in medaka fish confirmed both that the mutation has a pathogenic role and that the inactivation of this gene has a deleterious effect on photoreceptor cell function.


CONCLUSIONS
This study reveals that mutations in the ADAMTS18 gene can cause a broad phenotypic spectrum of eye disorders and contribute to shed further light on the complexity of retinal diseases.
Telethon Institute of Genetics and Medicine, via Pietro Castellino,111, Naples 80131, Italy.
Ivana
I
Peluso
Ivan
I
Conte
Francesco
F
Testa
Gopuraja
G
Dharmalingam
Mariateresa
M
Pizzo
Rob W J
RW
Collin
Nicola
N
Meola
Sara
S
Barbato
Margherita
M
Mutarelli
Carmela
C
Ziviello
Anna Maria
AM
Barbarulo
Vincenzo
V
Nigro
Mariarosa A B
MA
Melone
Francesca
F
Simonelli
Sandro
S
Banfi
D051722:ADAM Proteins / Q000235:genetics*; D000071096:ADAMTS Proteins; D017668:Age of Onset; D000595:Amino Acid Sequence; D000818:Animals; D005808:Genes, Recessive; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009990:Oryzias; D020641:Polymorphism, Single Nucleotide; D058499:Retinal Dystrophies / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D051722:ADAM Proteins; D000071096:ADAMTS Proteins; C510099:ADAMTS18 protein, human