Focal dermal hypoplasia is associated with mesodermal and ectodermal dysplasia.
Synonyms: Goltz Syndrome, Goltz-Gorlin Syndrome
Chromosome: Xp11.23
Gene: PORCN (probable protein-cysteine N-palmitoyltransferase porcupine), which is the human analoge to the Drosophila porcupine
Mutations: loss-of-function or deletions
Inheritance: X-linked dominant
Key clinical features:
(1) skin manifestations
(1a) hypoplastic or atrophic areas of skin
(1b) hyperpigmented or hypopigmented areas
(1c) cutis aplasia
(1d) verrucoid papillomas of skin
(1e) abnormal nails (ridged, hypoplasia or aplasia)
(1f) sparse or absent hair (scalp, eyebrows, areas of abnormal skin)
(1g) telangiectases
(1h) yellow-pink fat nodules in the dermis
(2) limb malformations
(2a) oligodactyly
(2b) syndactyly
(2c) split hand and/or foot malformations
(2d) camptodactyly
(2e) reduction defects in distal long bones (radius, ulna, tibia, fibula)
Other findings:
(1) verrucoid papillomas of mucous membranes
(2) osteopathia striata (seen in bone on plain radiographs)
(3) abnormalities of costovertebral segmentation (bifid ribs, fused ribs, butterfly vertebrae, hemivertebrae)
(4) diastasis pubis
(5) facial anomalies (notched alae nasi, pointed chin, small underfolded pinnae)
(6) dental anomalies
(7) abdominal wall defect
(8) diaphragmatic hernia
(9) renal anomalies (horseshoe kidney, absent kidney)
(10) ocular abnormalities (microphthalmia, anophthalmia, coloboma)
(11) lacrimal duct abnormalities
(12) cleft palate
(13) brittle hair
(14) gastroesophageal reflux
(15) short stature
Complications:
(1) fibrous dysplasia of bone
(2) giant cell tumor of bone
Many patients are mosaic for mutations in PORCN. This can be difficult to detect and associated with false negative genetic testing.
Testing should include:
(1) sequence analysis
(2) search for large deletions (for females with no mutations found on sequence analysis)
Specialty: Genetics
ICD-10: ,