TBCE and hypoparathyroidism-retardation-dysmorphism syndrome: In addition to HRD and KCS1, hypomorphic TBCE alleles have also been identified in patients with autosomal recessive Progressive Encephalopathy with Amyotrophy and Optic Atrophy (PEAMO; OMIM 617207), a distinctive neurodevelopmental/neurodegenerative disorder (15).