DHTKD1 and Global developmental delay: Four DHTKD1 variants detected in our ALS cohorts were previously described in patients with disorders affecting the nervous system, that is autosomal recessive AMOXAD, a metabolic condition characterized by elevated 2-aminoadipate and 2-oxoadipate levels in urine and/or plasma and varying neurological symptoms [9,10], autosomal recessive infantile-onset SMA with cognitive delay [12] and autosomal dominant CMT disease type 2Q (CMT2Q) [21], two neuromuscular disorders, as well as in patients with autosomal dominant eosinophilic esophagitis, sometimes accompanied by muscle weakness [25].