What is Focal Dermal Hypoplasia

Focal Dermal Hypoplasia, also known as Goltz syndrome, is a rare multisystem genetic disorder characterized by skin abnormalities, skeletal defects, and dental or ocular issues. It primarily affects tissues derived from the embryonic ectoderm and mesoderm, often resulting in linear patterns of thin or missing skin, fatty tissue protrusions, and irregular bone formation.

What are the primary symptoms of Focal Dermal Hypoplasia?

Focal Dermal Hypoplasia manifests differently in every individual, but the most distinctive feature is skin atrophy or aplasia. The skin may appear thin, discolored, or as reddish, fatty nodules. Because Focal Dermal Hypoplasia affects multiple systems, symptoms often include:

• Dermatological: Skin lesions following Blaschko’s lines, hyper- or hypopigmentation, and localized fatty tissue herniations.


• Skeletal: Missing or malformed digits (syndactyly or ectrodactyly) and spinal irregularities.


• Dental/Ocular: Enamel defects, microdontia (small teeth), coloboma (gap in eye structures), and microphthalmia.

What causes Focal Dermal Hypoplasia?

Focal Dermal Hypoplasia is caused by mutations in the PORCN gene located on the X chromosome. This gene is vital for the Wnt signaling pathway, which controls how cells communicate and develop during embryonic growth. In the DiseaseMaps.org community, 29 people have shared their experiences, highlighting the diverse ways this genetic mechanism impacts daily life.

Is Focal Dermal Hypoplasia hereditary?

Most cases of Focal Dermal Hypoplasia occur sporadically due to a new (de novo) mutation. Because it is an X-linked dominant condition, it is typically lethal in males, meaning the vast majority of diagnosed individuals are female. When it is inherited, it follows an X-linked dominant pattern, though the severity of the condition varies greatly due to a phenomenon called X-inactivation, where one X chromosome is randomly silenced in each cell.

How rare is Focal Dermal Hypoplasia?

Focal Dermal Hypoplasia is a very rare disorder, with an estimated prevalence of less than 1 in 10,000 to 1 in 50,000, though exact numbers are difficult to track due to underdiagnosis. It does not show a specific geographic bias and affects individuals globally regardless of ethnicity.

Next steps

• Consult a clinical geneticist to confirm the diagnosis through PORCN gene sequencing.


• Schedule multidisciplinary evaluations with dermatology, ophthalmology, and dentistry specialists.


• Join the DiseaseMaps.org community to connect with other families managing Focal Dermal Hypoplasia.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Focal Dermal Hypoplasia.


• Orphanet: Focal Dermal Hypoplasia (ORPHA362).


• OMIM (Online Mendelian Inheritance in Man): Focal Dermal Hypoplasia (#305600).


• National Foundation for Ectodermal Dysplasias (NFED).