Focal Dermal Hypoplasias, also known as Goltz syndrome or syndrome mosaïque, is a rare genetic disorder characterized by developmental abnormalities affecting multiple systems of the body, particularly the skin, skeletal system, eyes, and face. It is an X-linked dominant disorder, meaning that it is typically more severe in affected females, while affected males often exhibit milder symptoms.
The hallmark feature of focal dermal hypoplasias is the presence of focal areas of underdeveloped or missing skin, known as dermal hypoplasias or aplasias. These skin abnormalities may appear as thin, irregularly pigmented patches, which may be accompanied by the presence of lipomas or fatty tumors under the skin. Additionally, individuals with focal dermal hypoplasias may have abnormally shaped or missing fingers or toes, skeletal abnormalities such as bone cysts or extra bones, and short stature.
Other common features of focal dermal hypoplasias include abnormalities in the eyes, such as colobomas (holes or gaps in eye structures), strabismus (misalignment of the eyes), and cataracts. Facial anomalies, such as notched or bifid tongue, small chin, and wide-set eyes may also be present. Some individuals might experience hearing loss, dental abnormalities, kidney or gastrointestinal problems, or intellectual disability.
Diagnosis of focal dermal hypoplasias is based on clinical evaluation and the identification of characteristic symptoms. Molecular genetic testing may also be conducted to confirm the diagnosis by detecting mutations in the PORCN gene, responsible for encoding a protein involved in embryonic development.
Management of focal dermal hypoplasias involves a multidisciplinary approach, addressing the specific symptoms and complications that arise in each affected individual. Treatment options can include
