SNP Shot: Genomic Insights

Pulmonary alveolar microlithiasis (PAM) is a rare condition characterized by the gradual buildup of minuscule calcium phosphate stones (microliths) in the alveoli, which are the tiny air sacs within the lungs. This accumulation progressively injures the alveoli and the lung tissue around them, leading to interstitial lung disease and respiratory difficulties. Individuals with PAM may experience a chronic cough and shortness of breath (dyspnea), particularly during exercise. Chest pain, exacerbated by coughing, sneezing, or deep breathing, is also a possible symptom.

PAM is usually diagnosed before the age of 40, and is often detected incidentally during medical imaging performed for unrelated reasons, even before symptoms appear. The disease typically progresses slowly over many years, although some individuals may experience periods where their signs and symptoms remain constant.

In addition to the lungs, individuals with pulmonary alveolar microlithiasis can develop calcium phosphate deposits in other parts of the body, including the kidneys, gallbladder, testes, and the aortic valve (the valve between the aorta and the heart). Rarely, these deposits can lead to complications, such as aortic valve stenosis, which restricts blood flow.

Inheritance:

PAM is inherited in an autosomal recessive manner. This means that a person must inherit two copies of a mutated gene (one from each parent) to develop the condition. The parents, who each carry only one copy of the mutated gene, are typically asymptomatic carriers.