Chromosomal abnormalities affecting

the eye

By: Aditya ChaudhryRoll no. 77

Chromosomal deletion syndromes

• Cri-du Chat syndrome (5p)• Cri-du Chat syndrome (11p)• Cri-du Chat syndrome (13q)• De Grouchy syndrome (18q)• Turner syndrome (XO)

Cri-du- Chat syndrome • Its name is a French term (cat-cry or call of the cat) referring to the

characteristic cat-like cry of affected children.• The condition affects an estimated 1 in 50,000 live births.• More common in females by a 4:3 ratio.

Signs and symptoms:a. Feeding problems because of difficulty swallowing and sucking.b. Low birth weight and poor growth.c. Severe cognition, speech, and motor delays.d. Behavioural problems such as hyperactivity, aggression, tantrums, and

repetitive movements.e. Excessive drooling.f. Constipation.

Ocular manifestations in Cri-du- Chat (5p)

• Hypertelorism• Epicanthus• Antimongoloid slant• Strabismus

Hypertelorism

Before After correction

Epicanthus

Antimongoloid slant

Ocular manifestations in Cri-du- Chat (11p)

• Aniridia• Glaucoma• Foveal hypoplasia• Nystagmus• Ptosis

Aniridia Ptosis

Ocular manifestations in Cri-du- Chat (13q)

• Retinoblastoma• Hypertelorism• Micropthalmos• Epicanthus• Ptosis• Coloboma• Cataract

Microphthalmia

Coloboma

Retinoblastoma

De Grouchy Syndrome• Deletion of short arm of chromosome 18• Manifests as mental retardation, short stature, hypotonia.Ocular manifestations:i. Hypertelorismii. Epicanthusiii. Ptosisiv. Strabiusmusv. Myopiavi. Glaucomavii. Microphthalmosviii. Colobomaix. Optic atrophyx. Corneal opacity

Strabismus

Turner Syndrome• Monosomy X• Affected females have short stature, webbed neck, gonadal dysgenesis.

• Ocular manifestations:i. Antimongoloid slantii. Epicanthusiii. Ptosisiv. Strabismusv. Blue scleravi. Eccentric pupilsvii. Cataract viii. Colour blindnessix. Pigmentary disturbances of pupils

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