**Core Concept**
CREST syndrome is a limited cutaneous form of systemic sclerosis characterized by calcinosis, Raynaud’s phenomenon, esophageal dysfunction, sclerodermatous changes, and telangiectasias. It is primarily associated with specific autoantibodies, with anti-centromere antibodies being the most prevalent in this subset.

**Why the Correct Answer is Right**
In patients with limited cutaneous systemic sclerosis (CREST syndrome), over 90% produce anti-centromere antibodies (ACA). These antibodies target centromeric proteins in the nucleus and are strongly linked to the limited cutaneous form of scleroderma. ACA-positive patients typically present with milder skin involvement, less pulmonary arterial hypertension, and a better prognosis compared to anti-topoisomerase I-positive patients. The presence of ACA is highly specific for CREST syndrome and helps differentiate it from other connective tissue diseases.

**Why Each Wrong Option is Incorrect**
Option B: Anti-DNA topoisomerase I (anti-Scl-70) is associated with the **diffuse** cutaneous form of systemic sclerosis, not CREST syndrome, and is linked to more severe pulmonary and renal involvement.
Option C: Anti-double-stranded DNA is more common in systemic lupus erythematosus (SLE), not systemic sclerosis.
Option D: Anti-Golgi antibodies are seen in **mixed connective tissue disease** and are not specific to CREST syndrome.

**Clinical Pearl / High-Yield Fact**
Remember: **Anti-centromere antibodies = CREST syndrome**, and **anti-topoisomerase I = diffuse scleroderma**. This distinction is critical for prognosis and treatment planning.

✓ Correct Answer: A. Anti-centromere