Genes on Y chromosome protect against pulmonary hypertension, study suggests

FINDINGS A new UCLA study suggests that the Y chromosome provides protection against the development of pulmonary hypertension and may be the reason the disease is less prevalent among men than women. The researcher found that mice with Y chromosomes were significantly less likely to develop severe pulmonary hypertension than mice without Y chromosomes. The findings suggest for the first time that sex chromosomes — not only sex hormones — may explain why women, who typically do not have a Y chromosome, are more susceptible to the disease than men. BACKGROUND. Pulmonary hypertension, a chronic disease characterized by high blood pressure affecting the arteries and heart, appears most often in young women. It has no definitive cure and can be fatal. Many patients eventually require a lung transplant, a costly procedure that carries its own risks and requires a donor.