Rh-induced hemolytic disease of the fetus and newborn (HDFNRH) occurs in pregnancies in which mothers who lack the D antigen (RhD) of the Rh blood group (111690) have been exposed to the RhD-positive red cells of the fetus. The resulting maternal autoantibodies cross the placenta and destroy fetal red cells (summary by Urbaniak and Greiss, 2000).

Ventriculomegaly with cystic kidney disease is a severe autosomal recessive developmental disorder characterized by onset in utero of dilated cerebral ventricles and microscopic renal tubular cysts. The pregnancies of affected individuals are associated with increased alpha-fetoprotein (AFP). Most affected pregnancies have been terminated (summary by Slavotinek et al., 2015). See also 602200 for a disorder characterized by ventriculomegaly and defects of the radius and kidney.

Au-Kline syndrome is characterized by developmental delay and hypotonia with moderate-to-severe intellectual disability, and typical facial features that include long palpebral fissures, ptosis, shallow orbits, large and deeply grooved tongue, broad nose with a wide nasal bridge, and downturned mouth. There is frequently variable autonomic dysfunction (gastrointestinal dysmotility, high pain threshold, heat intolerance, recurrent fevers, abnormal sweating). Congenital heart disease, hydronephrosis, palate abnormalities, and oligodontia are also reported in the majority of affected individuals. Additional complications can include craniosynostosis, feeding difficulty, vision issues, osteopenia, and other skeletal anomalies.

Hydrops, lactic acidosis, and sideroblastic anemia (HLASA) is an autosomal recessive multisystem disorder characterized by the onset of hydrops in utero. The severity of the hydrops and the disorder in general is highly variable. At birth, affected infants usually show poor growth, lactic acidosis, pulmonary hypertension with hypoxic respiratory insufficiency, and sideroblastic anemia. More variable features may include hepatosplenomegaly or cholestasis, hypoglycemia, pancreatic insufficiency, and micropenis or hypospadias. Death in infancy may occur. Those who survive tend to have resolution of lactic acidosis and anemia, but may show developmental delay and sensorineural deafness (summary by Riley et al., 2020).

Lymphatic malformation-12 (LMPHM12) is characterized by abnormalities in the development and function of major truncal lymphatic vessels, causing nonimmune hydrops fetalis that results in stillbirth in some cases. Other affected individuals experience postnatal subcutaneous lymphedema and chylothorax, with pleural and pericardial effusions and ascites (Byrne et al., 2022). For a general phenotypic description and discussion of genetic heterogeneity of lymphatic malformation, see LMPHM1 (153100).

Lymphatic malformation-13 (LMPHM13) is characterized by the presence of nonimmune hydrops fetalis which often resolves with age. Capillary or cavernous hemangiomas are present in most patients, as are cardiac defects, often mild (Abdelrahman et al., 2018). For a discussion of genetic heterogeneity of lymphatic malformation, see 153100.