title: Three school-age cases of xeroderma pigmentosum variant type.
abstract: BACKGROUND
  Xeroderma pigmentosum (XP) is a photosensitive genodermatosis with increased susceptibility to skin cancers. Patients are typically diagnosed with XP when they consult a dermatologist for skin cancers.
  The genetic analysis and 2-8 years of follow-up for three school-age patients with XP-V is described. The patients were referred to us because of increased pigmented freckles; they had not experienced abnormal sunburn or developed skin cancer at their first visit. All patients harbored a genetic mutation in the POLH gene. XPV9KO was diagnosed at age 13 with a homozygous del1661A that creates a stop codon in the non-catalytic domain of POLH. The patient practiced sun protection, effectively preventing the development of skin cancer by age 21. XPV19KO was diagnosed at age 11 with a compound heterozygous mutation of G490T and C1066T, causing POLH truncation in the catalytic domain. This patient developed basal cell carcinoma at ages 12 and 13. XPV18KO was referred to us at age 11 and diagnosed with compound heterozygous variants of c.1246_1311del66 (exon 9 skipping), a novel mutation, and c.661_764 del104 (exon 6 skipping).
  
  
  CONCLUSIONS
  Freckle-like pigmentation on sun-exposed skin is sometimes the only sign of XP-V, and early diagnosis is extremely important for children.
authors: Division of Dermatology, Department of Internal Related,, Kobe University Graduate School of Medicine, Kobe, Japan.
authors: Ryusuke
authors: R
authors: Ono
authors: Taro
authors: T
authors: Masaki
authors: Seiji
authors: S
authors: Takeuchi
authors: Ayako
authors: A
authors: Shimizu
authors: Miki
authors: M
authors: Tanioka
authors: Naotomo
authors: N
authors: Kambe
authors: Hiroyuki
authors: H
authors: Matsue
authors: Ryoichi
authors: R
authors: Kamide
authors: Chikako
authors: C
authors: Nishigori
mesh_terms: D000293:Adolescent; D002648:Child; D018388:Codon, Terminator; D004259:DNA-Directed DNA Polymerase / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D005260:Female; D005500:Follow-Up Studies; D006579:Heterozygote; D006801:Humans; D008297:Male; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D014983:Xeroderma Pigmentosum / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000099270:Y-Family DNA Polymerases
chemical_list: D018388:Codon, Terminator; D004259:DNA-Directed DNA Polymerase; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases