Family With Sequence Similarity 21, Member D (FAM21D)

Due to duplication during evolution, human FAM21 exists as four highly homologous family members designated FAM21A, B, C and D. FAM21A, FAM21B and FAM21C, which are all alternatively known as WASH complex subunit FAM21A, B and C, respectively, are highly phosphorylated early endosomal membrane proteins that function as components of the WASH complex. FAM21D is the fourth, N-terminally truncated form of the FAM21 family which consists of 308 amino acids. All four family members are encoded by genes which map to human chromosome 10, which contains over 800 genes and 135 million nucleotides. PTEN is an important tumor suppressor gene located on chromosome 10 and, when defective, causes a genetic predisposition to cancer development known as Cowden syndrome. Other chromosome 10 associated disorders include Cockayne syndrome, tetrahydrobiopterin deficiency and trisomy 10.