Você conhece esta síndrome? Do you know this Syndrome?

A síndrome de Rothmund-Thomson é distúrbio autossômico recessivo de expressividade variável associado a mutações do gene RecQL4. Caracteriza-se por poiquilodermia, alopecia, defeitos de crescimento e desenvolvimento, catarata juvenil, alterações dentárias e esqueléticas e predisposição ao câncer cutâneo e ao osteossarcoma. Relata-se caso de paciente de 29 anos de idade com lesões cutâneas desde a infância, catarata bilateral antes dos 20 anos e carcinoma espinocelular aos 26 anos de idade.<br>Rothmund-Thomson syndrome is an autosomal recessive disorder of variable expression associated to mutations in the RECQL4 gene. Poikilodermatous rash, alopecia, growth and development defects, juvenile cataracts, dental abnormalities and predisposition to skin cancer and osteosarcoma are the main characteristics of this syndrome. The case of a 29-year-old woman with specific cutaneous lesions since childhood, bilateral cataracts before 20 years of age and squamous cell carcinoma at the age of 26 is reported

The RecQ4 Orthologue Hrq1 Is Critical for DNA Interstrand Cross-Link Repair and Genome Stability in Fission Yeast

Of the five human RecQ family helicases, RecQ4, BLM, and WRN suppress distinct genome instability-linked diseases with severe phenotypes, often with indeterminate etiologies. Here, we functionally define Hrq1, a novel orthologue of RecQ4 from fission yeast. Biochemical analysis of Hrq1 reveals a DEAH box- and ATP-dependent 3′-5′ helicase activity on various DNA substrates, including bubbles but not blunt duplexes, characteristic of the RecQ family. Cells lacking Hrq1 suffer spontaneous genomic instability and, consequently, require homologous recombination repair and the DNA damage checkpoint for viability. Hrq1 supports the nucleotide excision repair of DNA damage caused by the chemotherapeutic agent cisplatin and, in certain genetic contexts, UV light. Genetic epistasis analyses reveal that Hrq1 acts parallel to the PCNA/Ubc13/Mms2-dependent postreplication repair (PRR) pathway. Thus, in hrq1Δ cells, lesions are channeled through the PRR pathway, yielding hyperrecombinant and mutator phenotypes; analogous defects may underlie the genetic instability and diseases associated with RecQ4 dysfunction