Special AT-rich binding protein 2-associated syndrome: a case report and literature review

Abstract

Objective To retrospectively analyse the genetic characteristics, diagnosis, treatment and prognosis of special AT-rich binding protein 2 (SATB2)-associated syndrome. Methods Clinical data of one case of SATB2-associated syndrome diagnosed in Children′s Hospital Affiliated to Zhengzhou University in January 2018, were collected including clinical test, treatment plan, follow-up outcomes. The clinical characteristics of SATB2-associated syndrome were analyzed, and literature review was conducted. Results The female proband, eight-year-old, were admitted with the clinical manifestations including epilepsy seizures, delayed language development, sparse hair, long face, prominent forehead, long nose, lower eyelid cleft oblique, low ear, smooth philtrum, small mandible, sparse teeth arrangement, and lack of some teeth. The intelligence quotient score was 49. The brain magnetic resonance imaging showed myelinated dysplasia. Long-range video-electroencephalography showed spike-wave activity, slow spike-wave discharges in the bilateral middle and posterior temporal regions. The trio whole exome sequencing (trio WES) test showed that the proband carried a heterozygous nonsense mutation c.1300 C>T (p.Gln434Ter) in the SATB2 gene, and the muation was de novo comfirmed by pedigree analysis. Thirty-seven literatures relevant to SATB2-associated syndrome, from January 1989 to June 2019, were retrieved. Threre were 23 overseas literatures and one domestic report, including a total number of 158 cases. There were 49 missense mutations, 38 nonsense mutations, 32 frameshift mutations, seven splicing-site mutations, six translocation mutations, one insertion mutation, 22 gene-deletions and three gene-duplications. Among the 158 reported cases, 90 were male and 62 female, sex was not described in six cases. One hundred and fifty-eight (100.0%) patients had mental retardation, 44 (30.6%) with growth retardation, 107 (84.3%) with facial deformities, 70 (45.5%) with cleft palate, 135 (98.5%) with dental abnormalities, 66 (43.4%) with language retardation, 29 (20.0%) with epileptic seizures, and 50 (46.3%) with neuroimaging abnormalities. Conclusions The main clinical manifestations of SATB2-related syndromes are severe developmental retardation, low intelligence, delayed language development, language deficiency, high palatal arch and cleft palate, rare epilepsy seizures, dental anomalies and scant hair. The study identified a novel nonsense mutation c. 1300 C>T (p. Gln434Ter) in the SATB2 gene, which is responsible for the development of SATB2-associated syndrome. Key words: SATB2-associated syndrome; Genotype-phenotype correlation; Epilepsy; Mental retardation