After five years of indefinite testing yielding no accurate results, a whole-exome genome sequencing was performed revealing a de novo pathogenic heterozygous mutation in the ASXL3 gene in chromosome 18q12.1 associated with autosomal dominant BRPS. The gene discussed is ASXL3; the disease is severe feeding difficulties-failure to thrive-microcephaly due to ASXL3 deficiency syndrome.