[Diploid/triploid mosaicism: a variable but characteristic phenotype].

Abstract

INTRODUCTION:

Diploid/triploid mosaicism is a rare chromosomal abnormality. It is caused by a failure in the postzygotic division during embryonic development. It results in the coexistence of two genetically heterogeneous cell lines (46,XX and 69,XXX) in one individual. His clinical phenotype is characteristic. Pigmentary changes with a distribution pattern following Blaschko's lines abnormalities in other ectoderm-derived tissues are the main diagnostic signs.

CASE REPORTS:

Three cases of diploid/triploid mosaicism are described, and compared to the previously reported cases. The most frequently observed symptoms were mental retardation, truncal obesity, short stature, hemihypertrophy, small and narrow hands with clino and camptodactyly. Phenotypic characteristics of our three patients were similar to those of previously reported cases. Although there is no single and specific phenotype associated with mosaicism diploid/triploid, there are some dysmorphic features that shape a recognizable malformative syndrome. Peripheral blood lymphocytes karyotype was normal in our patients. Diagnosis was reached performing a fibroblast karyotype from hypopigmented skin.

CONCLUSIONS:

Intellectual disability associated with truncal obesity, short stature, hemihypertrophy or clino/camptodactyly should suggest to clinicians the possible existence of a diploid/triploid mosaicism. In most cases, karyotype from fibroblasts is needed to reach the diagnosis.

• Authors: Daniel Natera-De Benito, Pilar Poo, Esther Gean, Asunción Vicente-Villa, Angels García-Cazorla, M Carmen Fons-Estupiña
• Journal: Revista de neurologia (Rev Neurol) Vol. 59 Issue 4 Pg. 158-63 (Aug 16 2014) ISSN: 1576-6578 [Electronic] Spain
• Vernacular Title: Mosaicismo diploide/triploide: un fenotipo variable, pero característico.
• PMID: 25059266 (Publication Type: Case Reports, English Abstract, Journal Article, Review)

Topics

• Abnormal Karyotype
• Abnormalities, Multiple (genetics)
• Abortion, Habitual (genetics)
• Epilepsy, Absence (genetics)
• Face (abnormalities)
• Female
• Fetal Growth Retardation (etiology)
• Fibroblasts (ultrastructure)
• Heart Defects, Congenital (genetics)
• Humans
• Hypopigmentation (genetics)
• Infant, Newborn
• Infant, Small for Gestational Age
• Intellectual Disability (genetics)
• Lymphocytes (ultrastructure)
• Mosaicism
• Obesity, Abdominal (genetics)
• Phenotype
• Retrospective Studies
• Syndactyly (genetics)
• Triploidy