Question

A family pedigree reveals multiple individuals with symptoms such as progressive eye movement limitation, retinal pigment changes, and disturbances in cardiac conduction. Based on these findings and the inheritance pattern, which of the following is the most probable diagnosis?

• A. Duchenne Muscular Dystrophy
• B. Kearns--Sayre Syndrome
• C. Friedreich Ataxia
• D. Myotonic Dystrophy

Hint:

Progressive external ophthalmoplegia + pigmentary retinopathy + heart block = Kearns--Sayre syndrome.

Answer 1

The Correct Option is B

Concept: Kearns--Sayre syndrome is a mitochondrial disorder characterized by progressive external ophthalmoplegia, pigmentary retinopathy, and cardiac conduction defects.

Step 1: Identify the key clinical triad.
The patient has: \[ \text{Progressive eye movement limitation + retinal pigment changes + cardiac conduction defects} \] This is the classical triad of Kearns--Sayre syndrome.

Step 2: Understand the inheritance pattern.
Kearns--Sayre syndrome is related to mitochondrial DNA abnormality. Mitochondrial disorders commonly affect tissues with high energy requirement, such as eyes, muscles, heart, and nervous system.

Step 3: Select the most probable diagnosis.
Among the options, the condition that best matches ophthalmoplegia, pigmentary retinopathy, and conduction block is: \[ \text{Kearns--Sayre Syndrome} \] Therefore, the correct answer is Kearns--Sayre Syndrome.