title: A genotype-first approach for the molecular and clinical characterization of uncommon de novo microdeletion of 20q13.33.
abstract: BACKGROUND
  Subtelomeric deletions of the long arm of chromosome 20 are rare, with only 11 described in the literature. Clinical features of individuals with these microdeletions include severe limb malformations, skeletal abnormalities, growth retardation, developmental and speech delay, mental retardation, seizures and mild, non-specific dysmorphic features.
  
  
  RESULTS
  We characterized microdeletions at 20q13.33 in six individuals referred for genetic evaluation of developmental delay, mental retardation, and/or congenital anomalies. A comparison to previously reported cases of 20q13.33 microdeletion shows phenotypic overlap, with clinical features that include mental retardation, developmental delay, speech and language deficits, seizures, and behavior problems such as autistic spectrum disorder. There does not appear to be a clinically recognizable constellation of dysmorphic features among individuals with subtelomeric 20q microdeletions.
  
  
  CONCLUSIONS
  Based on genotype-phenotype correlation among individuals in this and previous studies, we discuss several possible candidate genes for specific clinical features, including ARFGAP1, CHRNA4 and KCNQ2 and neurodevelopmental deficits. Deletion of this region may play an important role in cognitive development.
authors.affiliation: Signature Genomic Laboratories, Spokane, Washington, United States of America.
authors.forename: Ryan N
authors.initials: RN
authors.lastname: Traylor
authors.forename: Damien L
authors.initials: DL
authors.lastname: Bruno
authors.forename: Trent
authors.initials: T
authors.lastname: Burgess
authors.forename: Robert
authors.initials: R
authors.lastname: Wildin
authors.forename: Anne
authors.initials: A
authors.lastname: Spencer
authors.forename: Devika
authors.initials: D
authors.lastname: Ganesamoorthy
authors.forename: David J
authors.initials: DJ
authors.lastname: Amor
authors.forename: Matthew
authors.initials: M
authors.lastname: Hunter
authors.forename: Michael
authors.initials: M
authors.lastname: Caplan
authors.forename: Jill A
authors.initials: JA
authors.lastname: Rosenfeld
authors.forename: Aaron
authors.initials: A
authors.lastname: Theisen
authors.forename: Beth S
authors.initials: BS
authors.lastname: Torchia
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Shaffer
authors.forename: Blake C
authors.initials: BC
authors.lastname: Ballif
authors.forename: Howard R
authors.initials: HR
authors.lastname: Slater
mesh_terms: D001526:Behavioral Symptoms / Q000235:genetics / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D002658:Developmental Disabilities / Q000235:genetics / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics / Q000503:physiopathology; D007806:Language Disorders / Q000235:genetics / Q000503:physiopathology; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D012640:Seizures / Q000235:genetics / Q000503:physiopathology; D013064:Speech Disorders / Q000235:genetics / Q000503:physiopathology
references.citation: Am J Hum Genet. 1999 Apr;64(4):1036-44
references.pmid: 10090888
references.citation: J Med Genet. 1987 Feb;24(2):93-6
references.pmid: 3560174
references.citation: Clin Genet. 2008 Nov;74(5):469-75
references.pmid: 18811697
references.citation: Am J Med Genet A. 2005 Apr 30;134(3):259-67
references.pmid: 15723295
references.citation: Eur J Hum Genet. 2007 Apr;15(4):446-52
references.pmid: 17290276
references.citation: Am J Med Genet A. 2005 Oct 15;138A(3):288-93
references.pmid: 16158442
references.citation: Mol Cytogenet. 2008 Apr 28;1:8
references.pmid: 18471269
references.citation: Hum Mol Genet. 2003 May 1;12(9):975-84
references.pmid: 12700166
references.citation: Traffic. 2007 Nov;8(11):1465-75
references.pmid: 17666108
references.citation: Clin Genet. 2008 May;73(5):492-5
references.pmid: 18341605
references.citation: J Med Genet. 1993 Feb;30(2):171-3
references.pmid: 8445626
references.citation: Am J Hum Genet. 2003 Jun;72(6):1470-8
references.pmid: 12740761
references.citation: Nature. 2008 Dec 4;456(7222):643-7
references.pmid: 18931657
references.citation: Proc Natl Acad Sci U S A. 2000 Feb 1;97(3):1212-7
references.pmid: 10655510
references.citation: J Neurochem. 2005 Jun;93(6):1444-53
references.pmid: 15935060
references.citation: J Med Genet. 2007 Dec;44(12):791-6
references.pmid: 17675531
references.citation: Am J Med Genet A. 2007 Aug 15;143A(16):1894-9
references.pmid: 17632785
references.citation: J Physiol. 2008 Jul 15;586(14):3405-23
references.pmid: 18483067
references.citation: Am J Med Genet A. 2010 Feb;152A(2):373-82
references.pmid: 20101690
references.citation: Mol Cytogenet. 2009 Aug 07;2:17
references.pmid: 19664229
references.citation: Nat Genet. 2000 Apr;24(4):434-7
references.pmid: 10742113
references.citation: Am J Med Genet A. 2005 Jan 15;132A(2):181-4
references.pmid: 15551337
references.citation: Am J Med Genet A. 2004 Aug 1;128A(4):352-63
references.pmid: 15264280
references.citation: Cancer Res. 2005 Jul 15;65(14):6071-9
references.pmid: 16024607
references.citation: Trends Cardiovasc Med. 2001 Nov;11(8):318-24
references.pmid: 11728880
references.citation: J Med Genet. 2006 Jun;43(6):478-89
references.pmid: 16199540
references.citation: J Neurol. 2004 Aug;251(8):923-34
references.pmid: 15316796
references.citation: Genet Med. 2007 Sep;9(9):607-16
references.pmid: 17873649
references.citation: Sem Hop. 1982 Jun 3;58(22):1366-9
references.pmid: 6287596
references.citation: Am J Med Genet. 2002 Nov 22;113(2):167-72
references.pmid: 12407707