Focal dermal hypoplasia (Goltz syndrome)

What is focal dermal hypoplasia?

Focal dermal hypoplasia (FDH) is a genetically inherited disorder that can affect the development of many different organ systems and was first described by Goltz in 1962. It presents with characteristic abnormalities of the skin, eyes and teeth and may also have effects on the skeletal, gastrointestinal, genitourinary, neurological and cardiovascular systems.

It is a rare condition with fewer than 300 cases reported, most of whom are female.

How do you get FDH?

FDH is genetically inherited in an X-linked dominant fashion. It is caused by abnormalities of the PORCN gene on the X chromosome, and most often these arise in the embryo and are not inherited from a parent. The X chromosome is one of the sex chromosomes: females are XX, males are XY. Females with one abnormal X chromosome are affected by FDH, but most males embryos with the abnormal gene do not survive.

FDH can affect almost any organ in the body. As with some other X-linked dominant conditions the skin manifestations follow developmental lines known as Blaschko lines.

What effects does it have?

FDH can have a wide range of effects on a variety of organ systems and the severity of the condition can vary greatly between individuals depending on the number of organs involved and the nature of the abnormalities.

Organ system	Abnormality
Skin	Linear hypoplastic (thinned) streaks which follow the lines of Blaschko Fat nodules and fat herniation Telangiectasia (visible superficial blood vessels) Verrucoid papillomas (warty growths) Pyogenic granuloma-like lesions Alopecia (thinning, balding, hair loss), brittle/sparse hair Nail abnormalities Palmar and plantar hyperkeratosis (thickened skin on hands and feet) Aplasia cutis congenita (localised total loss of skin) Hyperhidrosis (excessive sweating)
Eyes	Structural eye abnormalities: microphthamia (small eye), anophthalmia (missing eye) Displaced lens Choroidoretinal coloboma (missing retina and choroid) Optic nerve atrophy (lack of nerve supply to the eye) Blocked lacrimal (tear) duct
Musculoskeletal	Dental abnormalities: hypoplastic (small) teeth, abnormal enamel Microcephaly (small head), unilateral facial microsomia (underdeveloped face) Cleft lip and palate Low set ears Hand and foot abnormalities: ectrodactyly (lobster claw), brachydactyly (short fingers), oligodactyly (missing fingers), syndactyly (joined-up fingers) Abnormal vertebrae, bifid (double) or fused ribs, small collarbone Striated (striped) bones on X-ray
Renal	Structural kidney abnormalities: renal agenesis (missing kidney), horseshoe kidney, hydronephrosis (swollen kidney), bifid (split) ureter Bladder exstrophy (inside-out bladder)
Gastrointestinal	Oomphalocoele (abdominal contents outside the belly) Intestinal malrotation (twisted bowel) Anteriorly displaced anus Severe gastro-oesophageal reflux
Cardiac	Congenital heart disease
Neurological	Structural abnormalities of the cental nervous system: meningomyelocoele (spina bifida), hydrocephalus (swollen brain), Arnold-Chiari malformation (mishapen posterior brain), absent corpus callosum () Vision and hearing impairment Majority (>80%) reported to have normal psychological functioning

Focal dermal hypoplasia (Goltz syndrome)

What treatment is available?

Treatment will depend on the specialty care required for each specific problem. Often there will be specialists from multiple disciplines involved.

For cutaneous issues: telangectatic areas and papillomas may respond to vascular lasers; papillomas may be surgically removed if problematic.

Draft 24 September 2009

Related information

References:

Grzeschik, K-H, Bornholdt, D, Oeffner, F et al. Deficiency of PORCN, a regulator of Wnt signaling, is associated with focal dermal hypoplasia. Nature Genet. 39: 833-835; 2007.
Wang, X, Sutton, V. R, Peraza-Llanes, J. O, et al. Mutations in X-linked PORCN, a putative regulator of Wnt signaling, cause focal dermal hypoplasia. Nature Genet. 39: 836-838; 2007.
Textbook of Pediatric Dermatology 2nd Edition. Harper J, Oranje A, Prose N (Editors). Blackwell Science 2005.

Author: Dr Diana Purvis, Paediatric Dermatologist, and Dr Said Alkindi, Neonatal Fellow, Starship Hospital, Auckland, New Zealand.

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