Hypotrichosis 3, also known as hypotrichosis simplex of the scalp 2, is related to hypotrichosis 1 and mucinoses. An important gene associated with Hypotrichosis 3 is KRT74 (Keratin 74), and among its related pathways/superpathways is RAB geranylgeranylation. Related phenotypes are sparse scalp hair and abnormality of the dentition