Abstract: ObjectiveTo report a case of childhood apraxia of speech(CAS) caused by FOXP2 gene mutation, to summarize the clinical and genetic features of CAS, and to provide the basis for accurate diagnosis and outcome prediction of CAS. MethodsThe clinical features, Sanger testing, imageological examination, and follow-up of a patient carrying a heterozygous mutation of FOXP2 were summarized, and literatures about clinical features of CAS caused by FOXP2 gene mutations were reviewed. ResultsThe patient presented with language retardation at the age of 2 years and 5 months old. He was able to babble and understand parental commands but had no conscious verbal communication or spoken using phrases or "word combinations" . He was able to walk after 16 months of age. Minor morphologicals included epicanthic folds, arched eyebrows and flat-nosed. The physical examination found no abnormality while MR suggested otitis media and allergic rhinitis. The clinical-exome sequencing combined Sanger sequencing in proband confirmed a nonsense mutation in FOXP2 gene ［NM_014491: exon11, c.1432C>T(p.R478X)］, which was reported as a disease causing mutation of CAS (PMID: 27572252). The patient was diagnosed as CAS due to genetic test and clinical manifestation. The boy was followed up to 3 years old and he was able to pronounce monosyllable words and to call family member consciously. A total of 67 CAS cases that caused by FOXP2 mutations were retrieved in PubMed while there is no domestic report in CNKI and Wanfang database. All 68 cases were summarized including the case discussed in this article. The most frequent symptoms which related to speech-language disorder were abnormal pronunciation, followed by talking late, receptive and/or expressive language deficits and grammatical deficits. Moreover, multiple systems were involved with various manifestations. Thirty-four cases (50.7%) combined with neuromuscular problems. Twenty-four cases (35.8%) had craniofacial dysplasia. Twenty-one cases (31.3%) occurred below-average intelligence. Eight cases (11.9%) showed autistic features and 5 (35.8%) appeared abnormal skeletal joints. Besides, 5 cases of CAS with R478X presented with non-hearing loss, but 3 of them talked late while 1 had abnormal pronunciation and the other had difficulty in getting two words together. ConclusionGenetic test can provide the basis for accurate diagnosis of CAS and thus be helpful for appropriate treatment and family genetic counseling.