Unclassifiable pattern of hypopigmentation in a patient with mosaic partial 12p tetrasomy without Pallister–Killian syndrome

Viola Alesi, Maria L. Dentici, Fabrizia Restaldi, Valeria Orlando, Maria T. Liambo, Chiara Calacci, Rossella Capolino, Maria C. Digilio, May El Hachem, Antonio Novelli, Andrea Diociaiuti, Bruno Dallapiccola

Research output: Contribution to journalArticle

Abstract

Pallister–Killian syndrome (PKS-#OMIM601803) is a multisystem developmental disorder typically due to the presence of an aneuploidy cell line, consisting of a supernumerary tetrasomic chromosomal marker (SCM) arisen from the short arm of chromosome 12 (12p isochromosome). The clinical phenotype, which is strictly related to the percentage and tissue distribution of aneuploid cells, is characterized by craniofacial dysmorphisms, pigmentary skin anomalies, limb shortening, congenital heart defects, diaphragmatic hernia, hypotonia, intellectual disability, and epilepsy. We report on a 4 year-old girl harboring a 12p partial isochromosome, involving the PKS critical region, affecting about 70% of circulating lymphocytes, urine, and saliva cells and fibroblast from a hyperpigmented skin spot, and 100% of fibroblasts from a hypopigmented skin spot. Interestingly, despite the high proportion of affected cells this patient did not present with PKS, and a pattern of linear and patchy pigmentary mosaicism was the sole clinical manifestation. The present observation suggests that partial 12p SCM can also result in mild phenotypes, and its prevalence in the human population could have been underestimated. Accurate dermatologic evaluation could be a major handle for genetic testing.

Original languageEnglish
Pages (from-to)1943-1946
Number of pages4
JournalAmerican Journal of Medical Genetics, Part A
Volume173
Issue number7
DOIs
Publication statusPublished - Jul 1 2017

Fingerprint

Tetrasomy
Hypopigmentation
Isochromosomes
Aneuploidy
Skin
Fibroblasts
Phenotype
Chromosomes, Human, Pair 12
Muscle Hypotonia
Mosaicism
Diaphragmatic Hernia
Congenital Heart Defects
Genetic Testing
Tissue Distribution
Saliva
Intellectual Disability
Epilepsy
Extremities
Urine
Lymphocytes

Keywords

  • 12p isochromosome
  • 12p13.3
  • hypopigmentation
  • Pallister–Killian
  • skin dyschromia

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Cite this

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title = "Unclassifiable pattern of hypopigmentation in a patient with mosaic partial 12p tetrasomy without Pallister–Killian syndrome",
abstract = "Pallister–Killian syndrome (PKS-#OMIM601803) is a multisystem developmental disorder typically due to the presence of an aneuploidy cell line, consisting of a supernumerary tetrasomic chromosomal marker (SCM) arisen from the short arm of chromosome 12 (12p isochromosome). The clinical phenotype, which is strictly related to the percentage and tissue distribution of aneuploid cells, is characterized by craniofacial dysmorphisms, pigmentary skin anomalies, limb shortening, congenital heart defects, diaphragmatic hernia, hypotonia, intellectual disability, and epilepsy. We report on a 4 year-old girl harboring a 12p partial isochromosome, involving the PKS critical region, affecting about 70{\%} of circulating lymphocytes, urine, and saliva cells and fibroblast from a hyperpigmented skin spot, and 100{\%} of fibroblasts from a hypopigmented skin spot. Interestingly, despite the high proportion of affected cells this patient did not present with PKS, and a pattern of linear and patchy pigmentary mosaicism was the sole clinical manifestation. The present observation suggests that partial 12p SCM can also result in mild phenotypes, and its prevalence in the human population could have been underestimated. Accurate dermatologic evaluation could be a major handle for genetic testing.",
keywords = "12p isochromosome, 12p13.3, hypopigmentation, Pallister–Killian, skin dyschromia",
author = "Viola Alesi and Dentici, {Maria L.} and Fabrizia Restaldi and Valeria Orlando and Liambo, {Maria T.} and Chiara Calacci and Rossella Capolino and Digilio, {Maria C.} and {El Hachem}, May and Antonio Novelli and Andrea Diociaiuti and Bruno Dallapiccola",
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TY - JOUR

T1 - Unclassifiable pattern of hypopigmentation in a patient with mosaic partial 12p tetrasomy without Pallister–Killian syndrome

AU - Alesi, Viola

AU - Dentici, Maria L.

AU - Restaldi, Fabrizia

AU - Orlando, Valeria

AU - Liambo, Maria T.

AU - Calacci, Chiara

AU - Capolino, Rossella

AU - Digilio, Maria C.

AU - El Hachem, May

AU - Novelli, Antonio

AU - Diociaiuti, Andrea

AU - Dallapiccola, Bruno

PY - 2017/7/1

Y1 - 2017/7/1

N2 - Pallister–Killian syndrome (PKS-#OMIM601803) is a multisystem developmental disorder typically due to the presence of an aneuploidy cell line, consisting of a supernumerary tetrasomic chromosomal marker (SCM) arisen from the short arm of chromosome 12 (12p isochromosome). The clinical phenotype, which is strictly related to the percentage and tissue distribution of aneuploid cells, is characterized by craniofacial dysmorphisms, pigmentary skin anomalies, limb shortening, congenital heart defects, diaphragmatic hernia, hypotonia, intellectual disability, and epilepsy. We report on a 4 year-old girl harboring a 12p partial isochromosome, involving the PKS critical region, affecting about 70% of circulating lymphocytes, urine, and saliva cells and fibroblast from a hyperpigmented skin spot, and 100% of fibroblasts from a hypopigmented skin spot. Interestingly, despite the high proportion of affected cells this patient did not present with PKS, and a pattern of linear and patchy pigmentary mosaicism was the sole clinical manifestation. The present observation suggests that partial 12p SCM can also result in mild phenotypes, and its prevalence in the human population could have been underestimated. Accurate dermatologic evaluation could be a major handle for genetic testing.

AB - Pallister–Killian syndrome (PKS-#OMIM601803) is a multisystem developmental disorder typically due to the presence of an aneuploidy cell line, consisting of a supernumerary tetrasomic chromosomal marker (SCM) arisen from the short arm of chromosome 12 (12p isochromosome). The clinical phenotype, which is strictly related to the percentage and tissue distribution of aneuploid cells, is characterized by craniofacial dysmorphisms, pigmentary skin anomalies, limb shortening, congenital heart defects, diaphragmatic hernia, hypotonia, intellectual disability, and epilepsy. We report on a 4 year-old girl harboring a 12p partial isochromosome, involving the PKS critical region, affecting about 70% of circulating lymphocytes, urine, and saliva cells and fibroblast from a hyperpigmented skin spot, and 100% of fibroblasts from a hypopigmented skin spot. Interestingly, despite the high proportion of affected cells this patient did not present with PKS, and a pattern of linear and patchy pigmentary mosaicism was the sole clinical manifestation. The present observation suggests that partial 12p SCM can also result in mild phenotypes, and its prevalence in the human population could have been underestimated. Accurate dermatologic evaluation could be a major handle for genetic testing.

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KW - 12p13.3

KW - hypopigmentation

KW - Pallister–Killian

KW - skin dyschromia

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