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This abstract is assigned to session AOB Poster session 2 - Inflammatory pathology – Anterior segment – Ophthalmogenetics - Miscellaneous

Title	Microcoria due to a duplication at chromosome 13q32 and maternal mosaicism
Abstract Nr.	2034

Purpose	Microcoria is a congenital eye anomaly characterized by small pupillary opening. It is caused by an anomaly of the iris with absence of the muscle dilator of the pupil. In this case report, we describe a patient with non-syndromic microcoria du to a small duplication of the long arm of chromosome 13.
Methods	A 18-month-old girl is examined with no prior medical history. Refraction is impossible and dilatation cannot be obtained with cyclopentolate or atropine. The slit lamp examination shows a blue iris with very small pupils. Iris hypoplasia with absence of iris crypts and contraction folds is observed. The intraocular pressure (IOP) is normal in both eyes. The fundus is inaccessible because of the very small pupils. We performed biometry, tonometry, gonioscopy and fundus examination under narcosis. All examinations are normal. During the clinical follow up IOP is followed. We performed a genetic testing.
Results	The genetic anomaly observed is inherited by the mother, carrier of the duplication in a mosaic form. She presents a mild ocular phenotype. The duplication is detected by array comparative genomic hybridization. The exact breakpoints are characterized molecularly.
Conclusion	This case report confirms the previously reported locus on chromosome 13q as causal for non syndromic microcoria. This is the first description of a duplication in a patient with this phenotype and the presence of parental mosaicism. The possibility of mosaicism should be considered when genetic counselling is offered to the families.
Conflict of interest	No

Authors 1

Last name	POZZA
Initials	E
Department	C.H.U. Saint-Pierre
City	Brussels

Authors 2

Last name	Verdin
Initials	H
Department	U. Gent
City	Ghent

Authors 3

Last name	Menten
Initials	B
Department	U. Gent
City	Ghent

Authors 4

Last name	Deconinck
Initials	H
Department	Cliniques Sud Luxembourg
City	Arlon

Authors 5

Last name	Postolache
Initials	L
Department	HUDERF
City	Brussels

Authors 6

Last name	De Baere
Initials	E
Department	U. Gent
City	Ghent

Authors 7

Last name	Van Schil
Initials	K
Department	U. Gent
City	Ghent

Authors 8

Last name	Balikova
Initials	I
Department	HUDERF
City	Brussels