Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare X-linked dominant disorder affecting primarily females, with sporadic cases occurring in males as a result of post-zygotic mutations. Newborns can present with linear, streaky cutaneous atrophy with telangiectasias that follow Blaschko lines. They can also have ulcers at sites of congenital absence of skin that heal with atrophy. Soft red-yellow nodules (fat herniations) occur along Blaschko lines. Other abnormalities that can also be present at birth include: bone – syndactyly, polydactyly, oligodactyly with lobster-claw deformity and asymmetry; ocular – microphthalmia, anophthalmia, strabismus, coloboma, and aniridia; and aplasia cutis congenita.

Later, hypo- and hyperpigmentation with herniation of the subcutaneous fat occurs. Fleshy and vascular papillomas can develop on mucosal, perioral, perigenital, and intertriginous areas. Nail dystrophy, sparse hair, and intellectual disability can also be present. The characteristic bony finding on x-ray is vertical striations in the metaphysis of long bones called osteopathia striata. Osteopathia striata is generally found in older patients.

Patients with FDH generally have a normal lifespan but may be handicapped by skeletal deformities. The skin, eye, teeth, central nervous system, and skeletal anomalies can have other psychosocial consequences.