To analysze genotype and measure telomere length in two Chinese patients with dyskeratosis congenita(DC).
The peripleral blood DNA was extracted in two patients characterized by mucocutaneous abnormalities (abnormal nails, lacy reticulated skin pigmentation, and oral leukoplakia), bone marrow failure, DC genes were amplified by polymerase chain reaction (PCR), including DKC1, TERT, TERC, TINF2, NOP10, NHP2, then DNA sequencing was performed for abnormal exons. Lymphocyte telomere length was measured by flow cytometry-fluorescence in situ hybridization(Flow-FISH).
Abnormal peaks were found in exon 6 of TINF2 gene of the two patients and a 811C→T transition in TINF2 gene in one patient. DNA sequencing showed a 848C→A transition in TINF2 gene in another patient. Relative telomere length was remarkable less than that of normal children with same age.
Physician should think about DC if the young patients with mucocutaneous abnormalities and marrow failure. Early detection of related genes and measurernant of tolomere length may contribute to avoid misdiagnosis. TINF2 c.811C→T (Q271X) and TINF2 c.848C→A (P283H) exist in the two patients, it is reported in China for the first time.