**Question:** A 24 year old male presents to the clinic for routine checkup. On routine radiograph, supernumerary teeth are seen. General examination reveals hypermobility of shoulders and Gorlin sign is absent. What is the most probable diagnosis?

A. Supernumerary teeth
B. Ehlers-Danlos syndrome
C. Marfan syndrome
D. Hypohidrotic ectodermal dysplasia

**Core Concept:**
Supernumerary teeth are an abnormal condition where an individual has an extra tooth or teeth that do not belong to their normal complement of teeth. This can be seen in various genetic disorders or developmental abnormalities.

**Why the Correct Answer is Right:**
The correct answer is D, Hypohidrotic ectodermal dysplasia (HED) also known as Ectodermal Dysplasia Clefting (EDC), because the presence of supernumerary teeth, hypermobility of shoulders, and absence of Gorlin sign aligns with the clinical features of this disorder.

**Why Each Wrong Option is Incorrect:**
A) Supernumerary teeth can be seen in various conditions, but the other symptoms are not typically present in this condition.
B) Ehlers-Danlos syndrome is a connective tissue disorder, and the presence of supernumerary teeth is not a feature of this condition.
C) Marfan syndrome is a connective tissue disorder with features like tall stature, arachnodactyly, and lens dislocation, which are not seen in this case.

**Clinical Pearl:**
Hypohidrotic ectodermal dysplasia is a rare genetic disorder caused by mutations in the EDA gene. Clinical features include hypohidrosis (reduced sweating), hypodontia (missing teeth), and hypohidrosis (reduced sweating). In addition to these classic features, individuals with HED may also present with supernumerary teeth, which is consistent with the clinical findings in this case.

**Correct Answer Explanation:**
The correct answer, Hypohidrotic ectodermal dysplasia (HED), is a genetic disorder that affects ectodermal development. It is caused by mutations in the EDA gene and presents with reduced sweating (hypohidrosis), missing teeth (hypodontia), and reduced sweating (hypohidrosis). In addition to these classic features, individuals with HED may also present with supernumerary teeth, which is consistent with the clinical findings in this case.