MedGen

Syndromic thrombocytopenia-13 (THC13) is an autosomal recessive disorder characterized mainly by congenital thrombocytopenia resulting in increased bleeding. Platelets tend to be enlarged (macrothrombocytopenia) and/or gray and show functional defects. Some patients have infection-induced leukopenia or anemia and pancytopenia. Additional more variable features have also been reported, including mitral valve malformations, pyloric stenosis, and impaired intellectual development (Seo et al., 2019; Febres-Aldana et al., 2020; Marin-Quilez et al., 2023). For a discussion of genetic heterogeneity of thrombocytopenia, see THC1 (313900). [from OMIM]

Epimerase deficiency galactosemia (GALE deficiency galactosemia) is generally considered a continuum comprising several forms: Generalized. Enzyme activity is profoundly decreased in all tissues tested. Peripheral. Enzyme activity is deficient in red blood cells (RBC) and circulating white blood cells, but normal or near normal in all other tissues. Intermediate. Enzyme activity is deficient in red blood cells and circulating white blood cells and less than 50% of normal levels in other cells tested. Infants with generalized epimerase deficiency galactosemia develop clinical findings on a regular milk diet (which contains lactose, a disaccharide of galactose and glucose); manifestations include hypotonia, poor feeding, vomiting, weight loss, jaundice, hepatomegaly, liver dysfunction, aminoaciduria, and cataracts. Prompt removal of galactose/lactose from their diet resolves or prevents these acute symptoms. Longer-term features that may be seen in those with generalized epimerase deficiency include short stature, developmental delay, sensorineural hearing loss, and skeletal anomalies. In contrast, neonates with the peripheral or intermediate form generally remain clinically well even on a regular milk diet and are usually only identified by biochemical testing, often in newborn screening programs. [from GeneReviews]