Mosaic supernumerary inv dup(15) chromosome with four copies of the P gene in a boy with pigmentary dysplasia.
Association of the pink-eye-dilution gene (P) with hypopigmentation is seen in patients who have oculocutaneous albinism type 2 (OCA2) and Prader-Willi syndrome (PWS) or Angelman syndrome (AS). However, it remains unknown whether duplication or amplification of the P gene causes hyperpigmentation. We previously reported a woman who had hyperpigmentation with a duplication of the proximal part of 15q, including the P gene. Here, we describe an additional patient with mosaicism of inv dup(15) and clinical manifestations of severe psychmoter retardation, epilepsy, and pigmentary dysplasia showing mottled and linear patterns of hyperpigmentation. His karyotype was 47,XY,+idic(15)(pter-->q14::q14-->pter)[38]/46,XY[12] de novo. Chromosomal fluorescence in situ hybridization (FISH) showed six copies of the P gene. Therefore, his cutaneous mosaicism might be caused by the presence of both normal and hyperpigmented skin due to multicopies of the P gene.
Akahoshi
Keiko
K
Department of Medical Genetics, Tokyo Children's Rehabilitation Hospital, Tokyo, Japan. fwkt124@mb.infoweb.ne.jp
Spritz
Richard A
RA
Fukai
Kazuyoshi
K
Mitsui
Norimasa
N
Matsushima
Kazushige
K
Ohashi
Hirofumi
H
D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002871:Chromosome Banding; D007446:Chromosome Inversion; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D005260:Female; D020440:Gene Duplication; D006801:Humans; D017495:Hyperpigmentation / Q000235:genetics* / Q000473:pathology; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins; D009030:Mosaicism; D011596:Psychomotor Disorders / Q000235:genetics
D002352:Carrier Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C489600:OCA2 protein, human