**Core Concept**
Hereditary multiple exostoses (HME) is a rare genetic disorder characterized by the growth of multiple bony projections (exostoses) on the surface of long bones. This condition is primarily inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene is sufficient to cause the disorder.

**Why the Correct Answer is Right**
HME is caused by mutations in the EXT1 and EXT2 genes, which encode proteins involved in the synthesis of heparan sulfate, a type of glycosaminoglycan. These proteins play a crucial role in the regulation of bone growth and development. The mutations lead to the formation of multiple exostoses, which can cause various complications, including bone deformities, joint pain, and an increased risk of cancer. The autosomal dominant inheritance pattern means that children of an affected parent have a 50% chance of inheriting the mutated gene.

**Why Each Wrong Option is Incorrect**
**Option A:** HME is not inherited in an X-linked recessive pattern, as this would primarily affect males and is not consistent with the autosomal dominant inheritance pattern observed in HME.
**Option B:** While HME can be associated with other genetic disorders, it is not directly linked to the fragile X syndrome.
**Option C:** The inheritance pattern of HME is not autosomal recessive, as this would require two copies of the mutated gene (one from each parent) to cause the disorder.

**Clinical Pearl / High-Yield Fact**
HME is often diagnosed in childhood, and affected individuals may require regular monitoring for complications such as bone deformities, joint pain, and cancer.

**Correct Answer: D. Autosomal dominant inheritance.