GeneDx believes in responsible testing that is based on established medical guidelines, and we aim to be completely transparent with our pricing so that patients, clinicians, and payers know the cost of the test.
Both the skin findings and the deafness are heterogeneous in clinical presentation in these disorders. In some cases the deafness is congenital. In others there is later onset hearing loss of moderate degree. The dermatologic features associated with deafness and GJB2 mutations are also variable: in Vöhwinkel syndrome there is diffuse honeycomb hyperkeratosis of palms and soles with typical starfish keratoses on the dorsum. Pseudo-ainhum (constricting bands) and auto-amputation of digits may occur. The skin features of Bart-Pumphrey syndrome include hyperkeratotic plaques over knuckles and the dorsal digital joints (knuckle pads), leukonychia (white nails) and palmoplantar keratoderma. KID syndrome is an ectodermal dysplasia affecting the skin, hearing and vision and testing information is provided separately
Richard et al. Expanding the phenotypic spectrum of Cx26 disorders: Bart-Pumphrey Syndrome is caused by a novel missense mutation in GJB2. J Invest Dermatol, 123(5):856-63, 2004
Maestrini et al. A missense mutation in connexin26, D66H, causes mutilating keratoderma with sensorineural deafness (Vohwinkel\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s syndrome) in three unrelated families. Hum. Mol. Genet. 8: 1237–1243, 1999
G. Richard. Connexin Disorders of the Skin. Clinics in Dermatology, 23:23-32, 2005
Identification of the specific molecular basis of congential ichthyosis or related skin disorders
Genetic counseling and recurrence risk assessment
Preparation for prenatal testing in future pregnancies
As needed, based on the referring diagnosis and coverage achieved by the XomeDxSlice-Ichthyosis for a given patient, critical exons with a high yield of mutations will be filled-in by dideoxy sequencing. For any autosomal recessive gene, if one definitive mutation is found by XomeDxSlice sequencing, AND the gene fits the type of ichthyosis reported by the referring physician, capillary sequencing will be used to fill in sequence for exons that are not sufficiently covered (>10X) to find the second mutation. If no second mutation is found by sequencing, deletion/duplication analysis of that gene can be performed at no additional cost can be performed at no additional cost.
Patient samples sent for XomeDxSlice will not be evaluated for secondary findings and therefore will not receive secondary findings as part of their result.