Methods of treating decreased bone mineral density with cluster of differentiation 109 (CD109) inhibitors

A method of treating a subject with a therapeutic agent that treats or inhibits decreased bone mineral density, wherein the subject has decreased bone mineral density or is at risk of developing decreased bone mineral density, the method comprising the steps of:

• determining whether the subject has a Cluster of Differentiation 109 (CD109) missense variant nucleic acid molecule encoding a CD109 predicted loss-of-function polypeptide by:
• obtaining or having obtained a biological sample from the subject;
• and
• performing or having performed a sequence analysis on the biological sample to determine if the subject has a genotype comprising the CD109 missense variant nucleic acid molecule;
• and
• administering or continuing to administer the therapeutic agent that treats or inhibits decreased bone mineral density in a standard dosage amount to a subject that is CD109 reference, and/or administering a CD109 inhibitor to the subject, wherein the CD109 inhibitor comprises an inhibitory nucleic acid molecule that hybridizes to a CD109 nucleic acid molecule;
• administering or continuing to administer the therapeutic agent that treats or inhibits decreased bone mineral density in an amount that is the same as or less than a standard dosage amount to a subject that is heterozygous for the CD109 missense variant nucleic acid molecule, and/or administering a CD109 inhibitor to the subject, wherein the CD109 inhibitor comprises an inhibitory nucleic acid molecule that hybridizes to a CD109 nucleic acid molecule;
• or
• administering or continuing to administer the therapeutic agent that treats or inhibits decreased bone mineral density in an amount that is the same as or less than a standard dosage amount to a subject that is homozygous for the CD109 missense variant nucleic acid molecule;
• wherein the presence of a genotype having the CD109 missense variant nucleic acid molecule encoding the CD109 predicted loss-of-function polypeptide indicates the subject has a decreased risk of developing decreased bone mineral density.