EPOS

European Paediatric Ophthalmological Society

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Ocular findings in proximal trisomy 1q mosaicism

Dharmaraj Sharola, Maumenee Irene H.
¹The Johns Hopkins Center for Hereditary Eye Diseases, Johns Hopkins University, Baltimore, Maryland, USA.

Nondisjunction leading to trisomy is known to occur at either end of parental meiotic cell division. However mitotic nondysjunction is frequently associated with chromosomal mosaicism. Trisomy 1q is rare and we define the ocular characteristics in a patient with proximal trisomy 1q mosaicism with multiple congenital anomalies. The patient, a seventeen-year-old female, born of a non-consanguineous union presented with decreased vision at the ophthalmic clinic. Her past medical history included failure to thrive, mental retardation, cerebral palsy, hydrocephalus, psychomotor delay, intraventricular and choroidal plexus haemorrhage, seizure disorder, spastic quadriplegia with flexure contractures, Pierre-Robin syndrome (PRS), facial dysmorphism, narrow palpebral fissures, low set ears, hypoplasia of the external ear canals, reactive airway disease, Wolf-Parkinson- White syndrome, hypertrophic obstructive cardiomyopathy, posterior placed thumbs, severe scoliosis, bilateral dysplastic pelvis, syndactyly of the second and third toes of both feet, intestinal volvulus, primary ammenhorrea, haematocolpos, subseptate uterus and ovarian cysts. On examination the patient has facial dysmorphism, hemihypertrophy of the right side of face with gross thickening of the right zygomatic prominence, right occipital plagiocephaly, marked exorbitism, shallow orbits, synophyrs, narrowed palpebral fissures (16mm), bilateral distichiasis, exotropia (45PD), sluggishly reactive pupils, high myopia with astigmatism (-6+2x60 & -11+3x135) hyperpigmented maculae and pale optic nerves. The patient has normal extra ocular motility and is able to fix and follow objects at a distance of 3 feet. G-banding karyotype analysis using peripheral blood showed mosaicism, 46XX (dup)1q12-25,46XX.The clinical phenotype in trisomy 1q is characterized by psychomotor developmental delay and multiple congenital anomalies. The presence of a fragile site at 1q12 could explain the duplication resulting from an unequal crossover. Duplication of the 1q25 segment could also perhaps explain the presence of PRS and contractures.