MedGen

Adams-Oliver syndrome (AOS) is characterized by aplasia cutis congenita (ACC) of the scalp and terminal transverse limb defects (TTLD). ACC lesions usually occur in the midline of the parietal or occipital regions, but can also occur on the abdomen or limbs. At birth, an ACC lesion may already have the appearance of a healed scar. ACC lesions less than 5 cm often involve only the skin and almost always heal over a period of months; larger lesions are more likely to involve the skull and possibly the dura, and are at greater risk for complications, which can include infection, hemorrhage, or thrombosis, and can result in death. The limb defects range from mild (unilateral or bilateral short distal phalanges) to severe (complete absence of all toes or fingers, feet or hands, or more, often resembling an amputation). The lower extremities are almost always more severely affected than the upper extremities. Additional major features frequently include cardiovascular malformations/dysfunction (23%), brain anomalies, and less frequently renal, liver, and eye anomalies. [from GeneReviews]

Glycosylphosphatidylinositol is a glycolipid that anchors more than 150 proteins to the cell surface, and these proteins, termed GPI-anchored proteins (GPI-APs), perform a variety of functions as enzymes, adhesion molecules, complement regulators, and coreceptors in signal transduction pathways. Reduced surface levels of GPI-APs or abnormal GPI-AP structure can therefore result in variable manifestations. Glycosylphosphatidylinositol biosynthesis defect-1 (GPIBD1) is characterized predominantly by portal hypertension due to portal vein thrombosis. Most patients have absence seizures, cerebral thrombosis, and macrocephaly. Some patients have mildly to moderately impaired intellectual development (summary by Makrythanasis et al., 2016; Pode-Shakked et al., 2019). Genetic Heterogeneity of Glycosylphosphatidylinositol Biosynthesis Defects Also see GPIBD2 (239300), caused by mutation in the PIGV gene (610274); GPIBD3 (614080), caused by mutation in the PIGN gene (606097); GPIBD4 (300868), caused by mutation in the PIGA gene (311770); GPIBD5 (280000), caused by mutation in the PIGL gene (605947); GPIBD6 (614749), caused by mutation in the PIGO gene (614730); GPIBD7 (615398), caused by mutation in the PIGT gene (610272); GPIBD8 (614207), caused by mutation in the PGAP2 gene (615187); GPIBD9 (615802), caused by mutation in the PGAP1 gene (611655); GPIBD10 (615716), caused by mutation in the PGAP3 gene (611801); GPIBD11 (616025), caused by mutation in the PIGW gene (610275); GPIBD12 (616809), caused by mutation in the PIGY gene (610662); GPIBD13 (616917), caused by mutation in the PIGG gene (616918); GPIBD14 (617599), caused by mutation in the PIGP gene (605938); GPIBD15 (617810), caused by mutation in the GPAA1 gene (603048); GPIBD16 (617816), caused by mutation in the PIGC gene (601730); GPIBD17 (618010), caused by mutation in the PIGH gene (600154); GPIBD18 (618143), caused by mutation in the PIGS gene (610271); GPIBD19 (618548), caused by mutation in the PIGQ gene (605754); GPIBD20 (618580), caused by mutation in the PIGB gene (604122); GPIBD21 (618590), caused by mutation in the PIGU gene (608528); GPIBD22 (618879), caused by mutation in the PIGK gene (605087); GPIBD23 (617020), caused by mutation in the ARV1 gene (611647); GPIBD24 (619356), caused by mutation in the PIGF gene (600153); and GPIBD25 (619985), caused by mutation in the C18ORF32 gene (619979). [from OMIM]

Thrombosis of the portal vein and/or its tributaries, which include the splenic vein and the superior and inferior mesenteric veins. [from HPO]