Thomson syndrome Q82.8

Congenital poikiloderma characterized by the absence of consanguineousness, cataract, leukoplakia, blisters and verrucous keratoses, in contrast to the other congenital poikiloderma.

Because of the poor prognosis and high probability of degeneration of congenital poikiloderma with warty hyperkeratoses(Rothmund-Thomson syndrome), it is separated from Thomson syndrome by some authors, although they are the same genotype.

Autosomal recessive mutations of the RECQL4 gene (formerly: Rothmund-Thomson gene/RTS gene). RECQL4 stands for "RecQ Like Helicase 4" and is a protein coding gene located on chromosome 8q24.3. The protein RECQL4, encoded by this gene, is a DNA helicase belonging to the family of RecQ helicases.

Integument: Pale red, sometimes patchy, swollen skin. Development of reticulated telangiectasias, confluent pigmented spots, and well-demarcated depigmentation. Atrophic, dry, finely lamellar scaling skin. Partial lichenoid papules on the dorsum of the hand. Hypotrichosis (eyebrows, eyelashes, scalp).

Other symptoms: deformity or aplasia in the skeletal system. Triangular face, dental anomalies.

The distinction between Thomson syndrome and Rothmund-Thomson syndrome is no longer common today. In this respect, the name Rothmund-Thomson syndrome prevails. This syndrome, as well as Baller-Gerold syndrome, and RAPADILINO syndrome are associated with mutations in the RECQL4 gene. Because of the multiple overlapping signs and symptoms of these syndromes, it is believed to be a single syndrome with distinct phenotypes with overlapping symptoms.

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