Focal dermal hypoplasia (FDH)/Goltz syndrome

(OMIM #305600)

Focal dermal hypoplasia, or Goltz-Gorlin syndrome, is a rare syndrome, which may affect many different organs such as eyes, bones (limb malformation, osteopathia striata, costovertebral abnormalities, slipt sternum, fibrous dysplasia of bone, syndactyly, polydactyly, “lobster-clawlike” oligodactyly, short stature), teeth, and skin. To date, more than 280 cases of FDH have been reported in the literature. Clinical findings vary from mild skin atrophy to severe limb deformity and life-threatening complications. This disorder is inherited in an X-linked dominant manner, and occurs in females (90%). Approximately 95% of reported female cases occur sporadically as a result of de novo mutations. Mutation of PORCN (porcupine homolog) gene is closely associated with this disease. PORCN, located at Xp11.23, encodes the human homolog of Drosophila melanogaster Porcupine. Although the biochemical functions of the PORCN gene have not been completely characterized, it is known that Porcupine proteins are involved in the processing of Wnt (wingless and int homologue) proteins. Wnt signaling has been implicated in the embryonic development of the skin, bone, and other structures.

The goal of treatment is to improve specific system function and cosmetic appearance. Surgical interventions are often needed during childhood for the correction of skin, skeletal, intestinal, and ophthalmologic alterations. Therapeutic management includes: reconstructive surgery, and orthopedic surgery. Basic treatment for skin abnormalities is to promote healing and avoid infection. The flashlamp-pumped pulse dye laser has been reported to reduce pruritus and erythema and can flatten lesions. It has also been described that recalcitrant excessive granulation tissue could be treated with photodynamic therapy.

Gene

PORCN gene, Xp11.23 (OMIM gene/locus number #300651)

Phenotype

Short stature, mild microcephaly, facial asymmetry, pointed chin, protruding, simple and low-set ears, narrow auditory canals, hearing loss, mixed, strabismus, iris coloboma, aniridia, microphthalmia (15%), anophthalmia, choroidoretinal coloboma, ectopia lentis (6%), aniridia (3%), optic atrophy, nystagmus, decreased visual acuity, narrow nasal bridge, broad nasal tip, notched nasal alae, papillomas (lip and gingiva), cleft lip, cleft palate, hypodontia, oligodontia, enamel hypoplasia, delayed eruption, malocclusion, notched incisors, papillomatosis, midclavicular aplasia, midclavicular hypoplasia, rib hypoplasia, supernumerary nipples, symmetric breast, nipple hypoplasia, diaphragmatic hernia, umbilical hernia, omphalocele, diastasis recti, hiatus hernia, anteriorly displaced anus, intestinal malrotation, esophageal papillomas, inguinal hernia, clitoral hypoplasia, labial hypoplasia, cryptorchidism, horseshoe kidney, hydronephrosis, bifid ureter, skeletal asymmetry, joint laxity, asymmetric skull, failure of pubic bone fusion, congenital hip dislocation, osteopathia striata, syndactyly (75%), brachydactyly (60%), oligodactyly (45%), ectrodactyly, postaxial polydactyly, short phalanges, short metacarpal, short metatarsal, syndactyly, hypoplastic digits, missing toes, ectrodactyly, polydactyly, linear or reticular hyperpigmentation, skin atrophy, telangiectasia, localized cutaneous deposits of superficial fat, arborescent papillomas (axillae, periumbilical area, anus, vulva), hypoplastic fingertip epidermal ridges, hidrocystomas, dystrophic nails (spooned, grooves), absent fingernails, absent toenails, sparse hair, brittle hair, patchy alopecia (head, pubic area), mental retardation (15%), myelomeningocele, hydrocephalus, agenesis of corpus callosum, Arnold-Chiari malformation.

Images

Fig. (a)

Focal dermal hypoplasia (FDH)/Goltz syndrome

Fig. (b)

Focal dermal hypoplasia (FDH)/Goltz syndrome

Fig. (a) Syndactyly with lobster claw deformity of the left hand. (b) Oligodactyly and syndactyly of the left foot. 

Reproduced from Tenkir A, Teshome S, Goltz syndrome (focal dermal hypoplasia) with unilateral ocular, cutaneous and skeletal features: case report. BMC Ophthalmol 2010;10:28.


Other resources

 

References
  1. Murakami C, de Oliveira Lira Ortega A, Guimarães AS, et al.Focal dermal hypoplasia: a case report and literature review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011 Aug;112(2):e11-8.
  2. Lombardi MP, Bulk S, Celli J, et al. Mutation update for the PORCN gene. Hum Mutat. 2011 Jul;32(7):723-8.
  3. Wang L, Jin X, Zhao X, et al. Focal dermal hypoplasia: updates. Oral Dis. 2014 Jan;20(1):17-24.
  4. Masi L, Agnusdei D, Bilezikian J et al. Taxonomy of rare genetic metabolic bone disorders. Osteoporos Int. 2015 Jun 13.
  5. http://www.omim.org