[Two case reports].

Expansions of polyglutamine repeats are known to cause a variety of human neurodegenerative diseases. More recently, expansions of alanine tracts, particularly in transcription factor genes, have been shown to cause at least nine human conditions, including mental retardation and malformations of the brain, digits and other structures. Present knowledge suggests that alanine tract expansions generally, but not always, arise through unequal recombination as opposed to replication slippage, the most likely mechanism in other triplet repeat expansions. The function of alanine tracts is unknown but when alanine expansions occur in transcription factor genes, alanine tracts can result in either loss-of-function or gain of an abnormal function. Given the frequency of alanine tracts in proteins, it is likely that more alanine tract expansions will be discovered in disease genes.

Congenital Abnormalities↗

PubMed2004

Successful early surgical recruitment of the congenitally disconnected pulmonary artery.

BACKGROUND: Our purpose was to document our experience with early recruitment of congenitally disconnected pulmonary arteries and to assess subsequent pulmonary artery growth and function. METHODS: Patients born in the 10-year period from 1989 to 1999 with a disconnected pulmonary artery diagnosed in infancy and treated in our unit were studied. To be included patients had nonconfluent pulmonary arteries with one or both completely disconnected from the main pulmonary artery. This series did not include patients with acquired stenosis causing occlusion of a pulmonary artery. Echocardiography, cardiac catheterization, MRI, lung perfusion scans, and intraoperative assessment were used to gauge pulmonary artery growth and function. RESULTS: Seven patients with a disconnected pulmonary artery associated with intracardiac conotruncal congenital cardiac disease underwent successful early surgical recruitment of the affected pulmonary artery at 3 months of age or younger. Median follow-up from date of first operation was 4.2 years (range, 1.6 to 13.4). All 7 patients had postrecruitment lung perfusion scans showing a mean of 44% (range, 27% to 78%) of total pulmonary flow through the affected lung. Significant growth in the diameter of the recruited native pulmonary artery was demonstrated in all patients. There were no deaths reported in our series to date. CONCLUSIONS: The rare possibility of a congenitally disconnected pulmonary artery needs to be considered in all patients with a conotruncal cardiac anomaly. To facilitate surgical correction, ensure subsequent growth of the pulmonary artery, and optimize associated lung development, early diagnosis and surgical recruitment is recommended.

Congenital Abnormalities↗