Two Chinese Xia-Gibbs syndrome patients with partial growth hormone deficiency

Heterozygous mutations in the AT-hook DNA-binding motif containing one (AHDC1, OMIM * 615790) gene cause an autosomal dominant multisystem developmental disorder known as Xia-Gibbs syndrome (OMIM #615829). Xia-Gibbs syndrome typically presented with global developmental delay, hypotonia, obstructive sleep apnea, seizures, delayed myelination, micrognathia, and other mild dysmorphic features.

Description of the clinical materials of two Chinese boys who were diagnosed with Xia-Gibbs syndrome based on clinical presentations and next generation sequencing. Review of clinical features and AHDC1 mutations in previously reported Xia-Gibbs syndrome patients together with our two new patients.

The Xia-Gibbs syndrome patients exhibited short stature, hypotonia, global developmental delay, speech delay, simian crease, and mild dysmorphic features. Next generation sequencing revealed de novo heterozygous variants in AHDC1 gene. In addition, laboratory test revealed partial growth hormone deficiency. Both patients underwent growth hormone replacement therapy for 24 and 9 months, respectively, and exhibited good response to the treatment.

This is the first report of Xia-Gibbs syndrome patients to be treated with growth hormone. Review of previously reported Xia-Gibbs syndrome patient indicated that short stature is a frequent feature of this condition, but its underlying cause needs to be further investigated.