[Helsmoortel-Van der Aa syndrome due to hotspot mutation of ADNP gene and a literature review].

Objective: To summarize the clinical features and biological characteristics of Helsmoortel Van der Aa syndrome (HVDAS) due to hotspot mutations of the ADNP gene in order to facilitate early diagnosis.
Methods: Clinical data and result of genetic testing for a girl with HVDAS due to hotspot mutation of the ADNP gene was summarized. Related literature was also reviewed.
Results: The patient, a 2-year-old girl, had presented with growth retardation, facial dysmorphism, psychomotor and language delay and recurrent respiratory infections. Whole exome sequencing revealed that she has harbored a heterozygous c.2496_2499delTAAA (p.Asn832Lysfs*81) variant of the ADNP gene, which was not found in either of her parents.
Conclusion: Although the typical features of the HVDAS have included intellectual disability and autism spectrum disorders, growth retardation and premature primary tooth eruption may also be present. In addition, the phenotypic difference among individuals carrying hot spot variants of the ADNP gene was not prominent.