Further family investigation revealed that the patient’s reportedly healthy 6 months-old sister (patient III:5), who underwent prenatal chromosomal microarray analysis (CMA) testing harbored a genetic deletion in 17p11.2, encompassing the PMP22 gene, which is associated with Hereditary neuropathy with liability to pressure palsies syndrome (HNPP). This evidence concerns the gene PMP22 and hereditary neuropathy with liability to pressure palsies.