Paternal deletion of the GNAS imprinted locus (including Gnasxl) in two girls presenting with severe pre- and post-natal growth retardation and intractable feeding difficulties.
Deletions of the long arm of chromosome 20 are rare. Here, we report on two girls with a very small interstitial deletion of the long arm of chromosome 20 presenting with severe pre- and post-natal growth retardation, intractable feeding difficulties, abnormal subcutaneous adipose tissue, similar facial dysmorphism, psychomotor retardation and hypotonia. Standard cytogenetic studies were normal, but high-resolution chromosomes analysis showed the presence of a chromosome (20)(q13.2-q13.3) interstitial deletion. Karyotypes of both parents were normal. Molecular studies using FISH and microsatellite polymorphic markers showed that the deletion was of paternal origin and was approximatively 4.5 Mb in size. A review of other reported patients with similar deletions of the long arm of chromosome 20 shows that the observed phenotype might be explained in the light of the GNAS imprinted locus in particular by the absence of the Gnasxl paternally imprinted gene and the TFA2PC gene in the deleted genetic interval.
Geneviève
David
D
Département de Génétique, Hôpital Necker Enfants Malades, Paris, France. gendav@club-internet.fr
Sanlaville
Damien
D
Faivre
Laurence
L
Kottler
Marie-Laure
ML
Jambou
Marguerite
M
Gosset
Philippe
P
Boustani-Samara
Dinane
D
Pinto
Graziella
G
Ozilou
Catherine
C
Abeguilé
Geneviève
G
Munnich
Arnold
A
Romana
Serge
S
Raoul
Odile
O
Cormier-Daire
Valérie
V
Vekemans
Michel
M
D000328:Adult; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20; D020732:Cytogenetic Analysis / Q000379:methods; D005145:Face / Q000002:abnormalities*; D005220:Fathers; D005247:Feeding Behavior; D005260:Female; D018392:Genomic Imprinting / Q000235:genetics*; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D011247:Pregnancy