Congenital alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is characterized histologically by failure of formation and ingrowth of alveolar capillaries that then do not make contact with alveolar epithelium, medial muscular thickening of small pulmonary arterioles with muscularization of the intraacinar arterioles, thickened alveolar walls, and anomalously situated pulmonary veins running alongside pulmonary arterioles and sharing the same adventitial sheath. Less common features include a reduced number of alveoli and a patchy distribution of the histopathologic changes. The disorder is associated with persistent pulmonary hypertension of the neonate and shows varying degrees of lability and severity (Boggs et al., 1994). Affected infants present with respiratory distress resulting from pulmonary hypertension in the early postnatal period, and the disease is uniformly fatal within the newborn period (Vassal et al., 1998). Additional features of ACDMPV include multiple congenital anomalies affecting the cardiovascular, gastrointestinal, genitourinary, and musculoskeletal systems, as well as disruption of the normal right-left asymmetry of intrathoracic or intraabdominal organs (Sen et al., 2004).

Spondylocostal dysostosis (SCDO), defined radiographically as multiple segmentation defects of the vertebrae (M-SDV) in combination with abnormalities of the ribs, is characterized clinically by: a short trunk in proportion to height; short neck; non-progressive mild scoliosis in most affected individuals, and occasionally, more significant scoliosis. Respiratory function in neonates may be compromised by reduced size of the thorax. By age two years lung growth may improve sufficiently to support relatively normal growth and development; however, even then life-threatening complications can occur, especially pulmonary hypertension in children with severely restricted lung capacity from birth. Males with SCDO appear to be at increased risk for inguinal hernia.

Cornelia de Lange syndrome (CDLS) is a genetically heterogeneous developmental disorder characterized by malformations affecting multiple systems. Affected individuals have dysmorphic facial features, cleft palate, distal limb defects, growth retardation, and developmental delay. About 60% of patients have mutations in the NIPBL gene (608667) (summary by Musio et al., 2006 and Hoppman-Chaney et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of Cornelia de Lange syndrome, see CDLS1 (122470).