MedGen

Congenital disorders of glycosylation (CDGs) are a genetically heterogeneous group of autosomal recessive disorders caused by enzymatic defects in the synthesis and processing of asparagine (N)-linked glycans or oligosaccharides on glycoproteins. Type I CDGs comprise defects in the assembly of the dolichol lipid-linked oligosaccharide (LLO) chain and its transfer to the nascent protein. These disorders can be identified by a characteristic abnormal isoelectric focusing profile of plasma transferrin (Leroy, 2006). For a discussion of the classification of CDGs, see CDG1A (212065). CDG Ib is clinically distinct from most other CDGs by the lack of significant central nervous system involvement. The predominant symptoms are chronic diarrhea with failure to thrive and protein-losing enteropathy with coagulopathy. Some patients develop hepatic fibrosis. CDG Ib is also different from other CDGs in that it can be treated effectively with oral mannose supplementation, but can be fatal if untreated (Marquardt and Denecke, 2003). Thus, CDG Ib should be considered in the differential diagnosis of patients with unexplained hypoglycemia, chronic diarrhea, liver disease, or coagulopathy in order to allow early diagnosis and effective therapy (Vuillaumier-Barrot et al., 2002) Freeze and Aebi (1999) reviewed CDG Ib and CDG Ic (603147). Marques-da-Silva et al. (2017) systematically reviewed the literature concerning liver involvement in CDG. [from OMIM]

CDGs, previously called carbohydrate-deficient glycoprotein syndromes, grew from hereditary multisystem disorders first recognized by Jaeken et al. (1980). The characteristic biochemical abnormality of CDGs is the hypoglycosylation of glycoproteins, which is routinely determined by isoelectric focusing of serum transferrin. Type I CDG comprises those disorders in which there is a defect in the assembly of lipid-linked oligosaccharides or their transfer onto nascent glycoproteins, whereas type II CDG comprises defects of trimming, elongation, and processing of protein-bound glycans. For a general discussion of CDGs, see CDG1A (212065). CDG1H is a severe form of CDG. The majority of patients have brain involvement, liver pathology, gastrointestinal symptoms, dysmorphism (including brachydactyly), eye involvement (especially cataract), and skin symptoms. Most patients die within the first year of life (summary by Marques-da-Silva et al., 2017). [from OMIM]

Hennekam lymphangiectasia-lymphedema syndrome (HKLLS1) is an autosomal recessive disorder characterized by generalized lymphatic dysplasia affecting various organs, including the intestinal tract, pericardium, and limbs. Additional features of the disorder include facial dysmorphism and cognitive impairment (summary by Alders et al., 2014). Genetic Heterogeneity of Hennekam Lymphangiectasia-Lymphedema Syndrome See also HKLLS2 (616006), caused by mutation in the FAT4 gene (612411) on chromosome 4q28, and HKLLS3 (618154), caused by mutation in the ADAMTS3 gene (605011) on chromosome 4q13. [from OMIM]

IMD31C is a disorder of immunologic dysregulation with highly variable manifestations resulting from autosomal dominant gain-of-function mutations in STAT1 (600555). Most patients present in infancy or early childhood with chronic mucocutaneous candidiasis (CMC). Other highly variable features include recurrent bacterial, viral, fungal, and mycoplasmal infections, disseminated dimorphic fungal infections, enteropathy with villous atrophy, and autoimmune disorders, such as hypothyroidism or diabetes mellitus. A subset of patients show apparently nonimmunologic features, including osteopenia, delayed puberty, and intracranial aneurysms. Laboratory studies show increased activation of gamma-interferon (IFNG; 147570)-mediated inflammation (summary by Uzel et al., 2013 and Sampaio et al., 2013). [from OMIM]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the BLNK gene. [from MONDO]

Diarrhea-7 (DIAR7) is a protein-losing enteropathy characterized by early-onset nonbloody watery diarrhea and unresponsiveness to soy-based or elemental formulas. Patients experience failure to thrive, hypogammaglobulinemia with recurrent infections, and require albumin infusions and parenteral nutrition. Hypertriglyceridemia and digital clubbing have been observed (Stephen et al., 2016). The malabsorption can result in severe deficiency of vitamin D and other nutrients (Gupta et al., 2020). For a discussion of genetic heterogeneity of diarrhea, see DIAR1 (214700). [from OMIM]

Diarrhea-10 (DIAR10) is a protein-losing enteropathy characterized by intractable secretory diarrhea and massive protein loss due to leaky fenestrated capillaries. Features include early-onset anasarca, severe hypoalbuminemia, hypogammaglobulinemia, and hypertriglyceridemia, as well as electrolyte abnormalities. Some patients exhibit facial dysmorphism and cardiac and renal anomalies. Intrafamilial variability has been observed, and the disease can be severe, with death occurring in infancy in some patients (Broekaert et al., 2018; Kurolap et al., 2018). For a discussion of genetic heterogeneity of diarrhea, see DIAR1 (214700). [from OMIM]

Inflammatory bowel disease-30 (IBD30) is characterized by abdominal pain and watery or bloody diarrhea, with changes in the intestinal tract consistent with Crohn disease (Mao et al., 2018). For a general description and a discussion of genetic heterogeneity of inflammatory bowel disease, including Crohn disease (CD) and ulcerative colitis (UC), see IBD1 (266600). [from OMIM]

Cronkhite-Canada syndrome is characterized by gastrointestinal hamartomatous polyposis, alopecia, onychodystrophy, skin hyperpigmentation, and diarrhea. It is associated with high morbidity (summary by Sweetser et al., 2012). [from OMIM]

Hennekam lymphangiectasia-lymphedema syndrome-3 (HKKLLS3) is characterized by widespread congenital edema that is more severe in more dependent areas of the body. Associated features include facial dysmorphism and protein-losing enteropathy of variable severity (Brouillard et al., 2017). For a discussion of genetic heterogeneity of Hennekam lymphangiectasia-lymphedema syndrome, see HKLLS1 (235510). [from OMIM]

Oculoskeletodental syndrome (OCSKD) is characterized by congenital cataract, short stature and various skeletal anomalies, dysmorphic facial features and dental anomalies, developmental delay, and stroke. Other recurrent features include hearing loss, secondary glaucoma, and nephrocalcinosis (Tiosano et al., 2019). [from OMIM]

A rare genetic disease characterized by the presence of Müllerian duct derivatives (rudimentary uterus, fallopian tubes, and atretic vagina) and other genital anomalies (cryptorchidism, micropenis) in male newborns, intestinal and pulmonary lymphangiectasia, protein-losing enteropathy, hepatomegaly, and renal anomalies. Postaxial polydactyly, facial dysmorphism (including broad nasal bridge, bulbous nasal tip, long and prominent upper lip with smooth philtrum, hypertrophic alveolar ridges, and mild retrognathia, among other features), and short limbs have also been described. The syndrome is fatal in infancy. [from ORDO]

Mitochondrial complex IV deficiency nuclear type 19 (MC4DN19) is an autosomal recessive multisystem metabolic disorder characterized by the onset of symptoms in infancy or early childhood. Affected individuals show global developmental delay and developmental regression with a loss of acquired motor and language skills. Additional features include motor dysfunction, such as hypokinesia and pyramidal signs. More variable features may include recurrent infections with immunodeficiency and possibly protein-losing enteropathy. Serum lactate is increased; T2-weighted lesions in the medulla oblongata have also been reported. Patient tissues show decreased levels and activity of mitochondrial respiratory complex IV (Renkema et al., 2017). For a discussion of genetic heterogeneity of mitochondrial complex IV (cytochrome c oxidase) deficiency, see 220110. [from OMIM]

A rare systemic disease characterized by progressive hyalinosis involving capillaries, arterioles and small veins of the digestive tract, kidneys, and retina, associated with idiopathic cerebral calcifications, manifesting with severe diarrhea (with rectal bleeding and malabsorption), nephropathy (with renal failure and systemic hypertension), chorioretinal scarring, and subarachnoid hemorrhage. Poikiloderma and premature greying of the hair may be additionally observed. [from ORDO]

Severe congenital liver disease (SCOLIV) is an autosomal recessive disorder characterized by the onset of progressive hepatic dysfunction usually in the first years of life. Affected individuals show feeding difficulties with failure to thrive and features such as jaundice, hepatomegaly, and abdominal distension. Laboratory workup is consistent with hepatic insufficiency and may also show coagulation defects, anemia, or metabolic disturbances. Cirrhosis and hypernodularity are commonly observed on liver biopsy. Many patients die of liver failure in early childhood (Moreno Traspas et al., 2022). [from OMIM]

Complement hyperactivation, angiopathic thrombosis, and protein-losing enteropathy (CHAPLE) is characterized by abdominal pain and diarrhea, primary intestinal lymphangiectasia, hypoproteinemic edema, and malabsorption. Some patients also exhibit bowel inflammation, recurrent infections associated with hypogammaglobulinemia, and/or angiopathic thromboembolic disease. Patient T lymphocytes show increased complement activation, causing surface deposition of complement and generating soluble C5a (Ozen et al., 2017). [from OMIM]