Finally, we analyzed the residues involved in pathogenic substitutions in humans and leading to HOMGSMR1 (Hypomagnesemia, Seizures, and Impaired Intellectual Development 1 [43, 68–72], unpublished ClinVar submissions [73]) or HOMG6/HSMR (Hypomagnesemia 6, Renal/Hypomagnesemia, Seizures, and intellectual disability [74]) when present in CNNM2, and Jalili disorder (retinal cone-rod dystrophy and amelogenesis imperfecta [75–90], and unpublished ClinVar submissions [91]) when present in CNNM4. The gene discussed is CNNM4; the disease is familial primary hypomagnesemia.