Broad‐spectrum next‐generation sequencing‐based diagnosis of a case of Nager syndrome

Background Nager syndrome is a rare genetic syndrome characterized by craniofacial and preaxial limb anomalies. Haploinsufficiency of the SF3B4 gene has been identified as a significant reason for Nager syndrome. Treacher Collins syndrome (TCS) has similar facial features; however, the TCOF1 , POLR1D , and POLR1C genes have been reported as the critical disease‐causing genes. Similar phenotypes make it easy to misdiagnose. Case report In this report, we have presented a case of one newborn with acrofacial dysostosis, who was first diagnosed with TCS. Expanded next‐generation sequencing eventually detected a (c.1A>G) heterozygous mutation in the SF3B4 gene at chr1:149899651 that was confirmed by Sanger sequencing. Combined with his preaxial limb anomalies discovered after his death, a diagnosis of Nager syndrome was made. Conclusions This report presents one patient with Nager syndrome who was initially misdiagnosed with TCS. Correct genetic testing will be beneficial to future prenatal diagnosis.