GDAP1 and cystic fibrosis: Four of these decedents had compound heterozygous P/LP/VUS variants in genes associated with recessive disorders, including CFTR (cystic fibrosis), BCKDHA (maple syrup urine disease), MPDZ (congenital hydrocephalus-2), and GDAP1 (Charcot-Marie-Tooth disease, type 4A).