A neonate is noted to have epiphora, photophobia, and blepharospasm. Examination under anesthesia shows corneal diameter of 14 mm bilaterally with Haab's striae. Which statement about the genetic basis of this condition is most accurate?

• A Most sporadic; CYP1B1 gene mutation responsible for autosomal dominant forms
• B X-linked recessive; LTBP2 gene is causative
• C Autosomal dominant with variable penetrance; MYOC gene mutations responsible
• D Most commonly autosomal recessive; CYP1B1 gene mutation on chromosome 2p21 is the most common cause ✓

Explanation

Primary congenital glaucoma (buphthalmos) is most commonly autosomal recessive and is caused by mutations in the CYP1B1 gene (encoding cytochrome P4501B1) located on chromosome 2p21, particularly in consanguineous populations. Haab's striae (horizontal breaks in Descemet's membrane due to stretching) and corneal diameter >12 mm in a newborn are pathognomonic. LTBP2 is also implicated but less common. MYOC mutations cause juvenile open-angle glaucoma, not congenital glaucoma.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.