View abstract

This abstract is assigned to session AOB Poster session1

Title	Ocular non-nephropathic cystinosis due to a novel mutation in the lysosomal cystine transporter gene CTNS
Abstract Nr.	1025

Purpose	To describe a patient with ocular cystinosis, a rare AR metabolic disease characterized by the accumulation of cystine crystals, due to a novel mutation in the CTNS gene.
Methods	A 43-year old lady presented for routine examination. She underwent an extensive clinical and genetic work-up
Results	The patient was in good health. No ocular complaints. The BCVA was 10/10. Slit-lamp examination revealed small white reflective crystals spread in the anterior third of the corneal stroma in both eyes. Fundus examination showed no depigmentation or pigmentary mottling. Serum protein analysis to exclude a monoclonal gammopathy as cause of the corneal crystals was normal. Laboratory investigations and 24h urine collection showed a normal kidney function. Cystine concentration measured in leucocytes was 0,9 (nl <0,2 nmol half-cystine/mg protein) leading to a diagnosis of ocular, non-nephropathic, cystinosis. Genetic analysis with compound heterzygosity for the 57kb deletion and a novel c.635C>T mutation (p.Ala212Val) in the CTNS gene confirmed the clinical diagnosis.
Conclusion	The incidental finding of corneal crystals warrants a systemic work-up in search for the underlying cause. Renal involvement is heterogeneous in patients with non infantile cystinosis, even within families. Therefore genetic analysis confirming a clinical diagnosis of isolated ocular cystinosis without renal involvement is mandatory for appropriate counselling and treatment.

Authors 1

Last name	ACCOU
Initials	G.
Department	UNiversitair ziekenhuis Gent
City	Gent

Authors 2

Last name	De Craene
Initials	S.
Department	UZ Gent
City	Gent

Authors 3

Last name	Vanlerberghe
Initials	V
Department	Prive-praktijk
City	Beernem

Authors 4

Last name	Kestelyn
Initials	Ph
Department	Uz Gent
City	Gent

Authors 5

Last name	Leroy
Initials	BP
Department	Uz Gent
City	Gent

Authors 6

Last name	De Zaeytijd
Initials	J
Department	Uz Gent
City	Gent