Premium
Phenotype of FOXP2 haploinsufficiency in a mother and son
Author(s) -
Rice Gregory M.,
Raca Gordana,
Jakielski Kathy J.,
Laffin Jennifer J.,
IyamaKurtycz Christina M.,
Hartley Sigan L.,
Sprague Rae E.,
Heintzelman Anne T.,
Shriberg Lawrence D.
Publication year - 2012
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.34354
Subject(s) - foxp2 , haploinsufficiency , psychology , speech delay , apraxia , language disorder , developmental disorder , autism , phenotype , audiology , genetics , developmental psychology , medicine , cognition , neuroscience , aphasia , biology , gene , transcription factor
Disruptions in FOXP2 , a transcription factor, are the only known monogenic cause of speech and language impairment. We report on clinical findings for two new individuals with a submicroscopic deletion of FOXP2 : a boy with severe apraxia of speech and his currently moderately affected mother. A 1.57 Mb deletion on chromosome 7q31 was detected by array comparative genomic hybridization (aCGH). In addition to FOXP2 , the patients' deletion involves two other genes, MDFIC and PPP1R3A , neither of which has been associated with speech or language disorders. Thus, findings for these two family members provide informative phenotypic information on FOXP2 haploinsufficiency. Evaluation by a clinical geneticist indicated no major congenital anomalies or dysmorphic features. Evaluations by a clinical psychologist and occupational therapist indicated cognitive‐linguistic processing and sensorimotor control deficits, but did not support a diagnosis of autism spectrum disorder. Evaluation by clinical and research speech pathologists confirmed that both patients' speech deficits met contemporary criteria for apraxia of speech. Notably, the patients were not able to laugh, cough, or sneeze spontaneously, replicating findings reported for two other FOXP2 cases and a potential diagnostic sign of nonsyndromic apraxia of speech. Speech severity findings for the boy were not consistent with the hypothesis that loss of maternal FOXP2 should be relatively benign. Better understanding of the behavioral phenotype of FOXP2 disruptions will aid identification of patients, toward an eventual understanding of the pathophysiology of syndromic and nonsyndromic apraxia of speech. © 2011 Wiley Periodicals, Inc.