Alveolar capillary dysplasia, or ACD, is a rare, congenital and always fatal disorder. It is also known as misalignment of the pulmonary veins. More accurately, the pulmonary vein does not develop in the proper place, and thus, the alveolar capillaries that are responsible for the transfer of oxygen from the lungs to the blood, fail to develop in their proper positions.
ACD affects approximately one in 100,000 infants born. Symptoms usually present in full-term babies within 48 hours of birth, but sometimes can appear as long six weeks after birth (one infant presented with symptoms at seven months). The fact that some infants last longer tells doctors and scientists that there are different levels of severity of this condition and that, perhaps, provides hope for effective treatment. In these cases, the mothers usually report an unremarkable pregnancy.
Presenting symptoms are identical to persistent pulmonary hypertension of the newborn (signs of low oxygen, respiratory distress, and pulmonary hypertension). It is only when the treatments that usually work in the case of pulmonary hypertension don't work, that physicians can determine the symptoms be caused by ACD. A definitive diagnosis can only be confirmed on biopsy or autopsy.
The ACD Association (www.acd-association.com) reports that approximately 75 percent of all cases also present with other physiological anomalies (cardiovascular, gastrointestinal, urogenital, or musculoskeletal systems). In the 50 or so already reported cases, there is no apparent pattern to whether the condition affects boys more than girls or children born in certain environmental, economic, or social circumstances. Although six of the 50 cases have involved the presentation of symptoms in siblings, leading doctors and researchers to determine that there is an autosomal recessive inheritance factor in some cases.
The only treatment known at the moment is a lung transplant. Those infants who live longer obviously have a better chance of receiving a lung, but healthy infant lungs are hard to come by.