Patients with a vitamin D deficiency had more often comorbidity (100% Vs 87.6%; p = 0.02), a significantly lower mean serum corrected calcium concentration (2.33 mmol/L Vs 2.37 mmol/L; p = 0.03) and higher mean serum PTH (6.4 pmol/L Vs 4.4 pmol/L; p < 0.001). The gene discussed is PTH; the disease is vitamin D deficiency.