Palmoplantar keratoderma and erythrokeratodermas

Gene: RSPO1

Green List (high evidence)

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
palmoplantar keratoderma; SCC of skin; sex reversal

Comment on list classification: Updated rating from Amber to Green: 1 green review plus sufficient (3) cases to support causation of PPK phenotype.

Created: 20 Mar 2017, 12:36 p.m.

Comment on list classification: Updated rating from Red to Amber ready for external review. 3 unrelated cases of RSPO1 mutations linked to OMIM:610644.

Created: 10 Jan 2017, 4:45 p.m.

In a 40-year-old 46, XX SRY-negative woman with true hermaphroditism and palmoplantar keratoderma (OMIM:610644), whose parents were first cousins, Tomaselli et al. (2008, PMID:18085567) identified homozygosity for a 286+1G-A transition altering the splice donor site in intron 5 of the RSPO1 gene.

Created: 10 Jan 2017, 4:42 p.m.

In a sporadic case of palmoplantar hyperkeratosis with squamous cell carcinoma of skin and sex reversal (610644), Parma et al. (2006) identified a homozygous deletion of 2,752 bp, including exon 4 and part of the adjacent introns.

Created: 10 Jan 2017, 4:41 p.m.

In a consanguineous family from southern Italy affected by palmoplantar hyperkeratosis with squamous cell carcinoma of skin and sex reversal (610644), Parma et al. (2006, PMID:17041600) found a homozygous 1 bp insertion (896G) in the RSPO1 gene. The mutation resulted in a frameshift and stop codon after 10 amino acids.

Created: 10 Jan 2017, 4:41 p.m.