**Question:** Finger is glove sign is seen in

A. Cystinosis
B. Tay-Sachs disease
C. Fabry disease
D. Niemann-Pick disease

**Core Concept:** The Finger is Glove sign is a rare clinical sign seen in lysosomal storage disorders, particularly those affecting the lysosomes of the mononuclear phagocytic system. Lysosomes are membrane-bound organelles in cells that contain hydrolytic enzymes responsible for breaking down various molecules. Lysosomal storage disorders are caused by defective enzymes or transport proteins leading to the accumulation of undegraded substances within lysosomes.

**Why the Correct Answer is Right:** The correct answer, Niemann-Pick disease, is a lysosomal storage disorder characterized by the accumulation of cholesterol and sphingolipids in macrophages, leading to the infiltration of various organs and tissues. The Finger is Glove sign is a result of the accumulation of cholesterol and sphingolipids in the subcutaneous tissues, causing a glove-like distribution of the infiltration.

**Why Each Wrong Option is Incorrect:**

A. Cystinosis is a disorder characterized by the accumulation of cystine in cells, specifically in lysosomes. The Finger is Glove sign is not seen in cystinosis.

B. Tay-Sachs disease is another lysosomal storage disorder, but it involves the accumulation of sphingolipids, not cholesterol, in the brain and peripheral nervous system, making the Finger is Glove sign less likely.

C. Fabry disease is a lysosomal storage disorder caused by the deficiency of α-galactosidase enzyme, leading to the accumulation of globotriaosylceramide in various tissues and organs. The Finger is Glove sign is not a typical presentation in Fabry disease.

**Clinical Pearl:** The Finger is Glove sign is a rare and specific clinical sign, often seen in Niemann-Pick disease type C. This sign should prompt the clinician to consider lysosomal storage disorders in the differential diagnosis, as it can help differentiate these conditions from other similar presentations.

**Correct Answer:** Niemann-Pick disease type C

**Core Concept:** Niemann-Pick disease type C is a lysosomal storage disorder caused by the deficiency of sphingolipid glucosylceramidase enzyme, leading to the accumulation of sphingolipids in macrophages and Kupffer cells, resulting in the infiltration of the liver, lungs, spleen, and central nervous system. This accumulation leads to the development of the Finger is Glove sign, which is characterized by the infiltration of subcutaneous tissues and the formation of sphingomyelin crystals.

**Why the Correct Answer is Right:** This lysosomal storage disorder affects various organs and tissues, including the subcutaneous tissues, leading to the accumulation of sphingomyelin crystals. This results in the characteristic clinical presentation of the Finger is Glove sign.

**Why Each Wrong Option is Incorrect:**

A. Cystinosis: This is a lysosomal storage disorder caused by cystine accumulation in lysosomes, affecting primarily the kidneys, lungs