Focal dermal hypoplasia (FDH) is a rare genetic disorder of ectodermal dysplasia caused by mutation in the Porcupine Homolog (Drosophila) (PORCN) gene which results in skin, hair, limb and eye abnormalities. Short stature and underweight have been noted in the majority of these patients. Since the pituitary gland arises from ectodermal tissue, the investigators suspect that pituitary deficiencies may contribute to poor linear growth. This study will examine the nutritional, gastrointestinal and endocrine mechanisms that may account for linear growth stunting and low weight that is observed in FDH. The investigators will utilize standard clinical tools including a bone age xray, glucagon stimulation test to evaluate growth hormone status, baseline laboratory analysis of hormone and nutritional/gastrointestinal markers, food diaries, symptom diaries, and growth charts.

Focal dermal hypoplasia (FDH) is a rare genetic disorder of ectodermal dysplasia caused by mutation in the Porcupine Homolog (Drosophila) (PORCN) gene which results in skin, hair, limb and eye abnormalities. Short stature and underweight have been noted in the majority of these patients. Since the pituitary gland arises from ectodermal tissue, the investigators suspect that pituitary deficiencies may contribute to poor linear growth. This study will examine the nutritional, gastrointestinal and endocrine mechanisms that may account for linear growth stunting and low weight that is observed in FDH. The investigators will utilize standard clinical tools including a bone age xray, glucagon stimulation test to evaluate growth hormone status, baseline laboratory analysis of hormone and nutritional/gastrointestinal markers, food diaries, symptom diaries, and growth charts.

Inclusion Criteria:

• patients with focal dermal hypoplasia
• between the ages of 3 and 18 years
• ability to fast overnight, and
• weight at least 9 kg

Exclusion Criteria:

• pregnant individuals,
• weight less than 9 kg

Children with focal dermal hypoplasia