Clinical and genetic characteristics of a case of Koolen-De Vries syndrome caused by KANSL1 gene mutation and literature review: A case report.

RATIONALE

Koolen-De Vries syndrome (KdVS, OMIM: 612452), also known as 17q21.31 microdeletion syndrome, is an autosomal dominant genetic disease. In the study, we analyze of clinical phenotype and gene variation of a child with Koolen-De Vries syndrome, review the literature to improve the understanding of the disease.

PATIENT CONCERNS

The patient is a male, aged 1 month and 3 days. The patient has poor airway development, difficulty weaning from respiratory support, seizures, and recurrent low granulocyte counts.

DIAGNOSES

High-throughput sequencing showed a heterozygous mutation NM_001193466.1: c.1574_1578del (P.525HFS *24) in the KANSL1 gene of the proband, which was considered a new mutation since neither of his parents carried this mutation based on Sanger sequencing results. Combining clinical features and genetic results, the proband was diagnosed as KdVS.

INTERVENTIONS AND OUTCOMES

The patient was in good condition after receiving bronchoscopy and laser interventional therapy, meeting the criteria for discharge. Follow-up for 1 year and 6 months indicated that the patient's physical signs were normal and there was no recurrence.

LESSONS

According to literature review, KdVS is a multi-organ disease characterized by feeding difficulties, seizures, characteristic facial features, dysplasia of the respiratory system and cardiac abnormalities. In this study, laryngeal malacia accounted for 23.2% of the clinical manifestations of KdVS patients, limb convulsions/seizures accounted for 62.5%, and cardiac development defects accounted for 23.5%. The disease was rare in China and had a variety of clinical manifestations. The summary of reported cases can enable doctors to have more understanding of the disease. The new mutations enrich the KANSL1 gene mutation spectrum.