title: Translocation (X;13)(p11.21;q12.3) in a girl with incontinentia pigmenti and bilateral retinoblastoma.
abstract: A de novo t(X;13)(p11.21;q12.3) translocation is described in an 19-month-old girl with incontinentia pigmenti (IP) and bilateral retinoblastoma. Based on previously reported two girls and this patient, each with a structural X chromosome abnormality and IP, it was assumed that the locus for IP is at Xp11.21. Q-banding analysis revealed that the translocated chromosomes were of paternal origin. The derivative X chromosome was late-replicating in 9% of cultured peripheral blood lymphocytes and in 1% of skin fibroblasts. The erythrocyte esterase D activity in the patient was normal. Several possibilities were considered for possible causative relationship between the X/13 translocation and the development of retinoblastoma. One possibility involved functional monosomy of 13q14 in a minority of retinoblasts due to the spreading of inactivation of the translocated X chromosome segment.
mesh_terms: D002871:Chromosome Banding; D002901:Chromosomes, Human, 13-15; D004261:DNA Replication; D005134:Eye Neoplasms / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D007621:Karyotyping; D010859:Pigmentation Disorders / Q000235:genetics*; D012175:Retinoblastoma / Q000235:genetics*; D014178:Translocation, Genetic; D014960:X Chromosome