As compared to the typical dominant phenotype, the recessive phenotype ranged from similar e.g. SLC20A2-related Basal ganglia calcification in family F4159 (Fig. 2h), TCOF1-related Treacher-Collin syndrome in family F732 (Fig. 2i) and MAPRE2-related circumferential skin creases in family F531, to more severe e.g. ADSS1-related embryonic lethality in family F8399, to distinct allelic disorders. This evidence concerns the gene SLC20A2 and Treacher-Collins syndrome.