MedGen

Mucolipidosis III gamma (ML III?) is a slowly progressive inborn error of metabolism mainly affecting skeletal, joint, and connective tissues. Clinical onset is in early childhood; the progressive course results in severe functional impairment and significant morbidity from chronic pain. Cardiorespiratory complications (restrictive lung disease from thoracic involvement, and thickening and insufficiency of the mitral and aortic valves) are rarely clinically significant. A few (probably <10%) affected individuals display mild cognitive impairment. [from GeneReviews]

Retinitis pigmentosa (RP) refers to a heterogeneous group of inherited ocular diseases that result in a progressive retinal degeneration affecting 1 in 3,000 to 5,000 people (Veltel et al., 2008). Symptoms include night blindness, the development of tunnel vision, and slowly progressive decreased central vision starting at approximately 20 years of age. Upon examination, patients have decreased visual acuity, constricted visual fields, dyschromatopsia (tritanopic; see 190900), and the classic fundus appearance with dark pigmentary clumps in the midperiphery and perivenous areas ('bone spicules'), attenuated retinal vessels, cystoid macular edema, fine pigmented vitreous cells, and waxy optic disc pallor. RP is associated with posterior subcapsular cataracts in 39 to 72% of patients, high myopia, astigmatism, keratoconus, and mild hearing loss in 30% of patients (excluding patients with Usher syndrome; see 276900). Fifty percent of female carriers of X-linked RP have a golden reflex in the posterior pole (summary by Kaiser et al., 2004). Juvenile Retinitis Pigmentosa Autosomal recessive childhood-onset severe retinal dystrophy is a heterogeneous group of disorders affecting rod and cone photoreceptors simultaneously. The most severe cases are termed Leber congenital amaurosis (see 204000), whereas the less aggressive forms are usually considered juvenile retinitis pigmentosa (Gu et al., 1997). Autosomal recessive forms of juvenile retinitis pigmentosa can be caused by mutation in the SPATA7 (609868), LRAT (604863), and TULP1 (602280) genes (see LCA3, 604232, LCA14, 613341, and LCA15, 613843, respectively). An autosomal dominant form of juvenile retinitis pigmentosa (see 604393) is caused by mutation in the AIPL1 gene (604392). [from OMIM]

Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography. [from GeneReviews]

Hereditary primary lymphedema is caused by anatomic or functional defects in the lymphatic system, resulting in chronic swelling of body parts. There may be accompanying nail and skin changes, such as nail dysplasia or papillomatosis. Onset is usually at birth or in early childhood but can occur later, and the severity is variable (summary by Gordon et al., 2013 and Balboa-Beltran et al., 2014). For a discussion of genetic heterogeneity of lymphatic malformation, see 153100. [from OMIM]

Familial cold autoinflammatory syndrome-3 is an autosomal dominant immune disorder characterized by the development of cutaneous urticaria, erythema, and pruritus in response to cold exposure. Affected individuals have variable additional immunologic defects, including antibody deficiency, decreased numbers of B cells, defective B cells, increased susceptibility to infection, and increased risk of autoimmune disorders (summary by Ombrello et al., 2012). For a discussion of genetic heterogeneity of FCAS, see FCAS1 (120100). [from OMIM]

Bronchiectasis with or without elevated sweat chloride-3 (BESC3) is characterized by dilation of the airways arising from chronic bronchial inflammation accompanied by chronic cough, purulent sputum, and recurrent lower respiratory tract infections. Most patients show some degree of airflow obstruction (Fajac et al., 2008). [from OMIM]

The signs and symptoms of PFIC2 are typically related to liver disease only; however, these signs and symptoms tend to be more severe than those experienced by people with PFIC1. People with PFIC2 often develop liver failure within the first few years of life. Additionally, affected individuals are at increased risk of developing a type of liver cancer called hepatocellular carcinoma.

In addition to signs and symptoms related to liver disease, people with PFIC1 may have short stature, deafness, diarrhea, inflammation of the pancreas (pancreatitis), and low levels of fat-soluble vitamins (vitamins A, D, E, and K) in the blood. Affected individuals typically develop liver failure before adulthood.

There are three known types of PFIC: PFIC1, PFIC2, and PFIC3. The types are also sometimes described as shortages of particular proteins needed for normal liver function. Each type has a different genetic cause.

Signs and symptoms of PFIC typically begin in infancy and are related to bile buildup and liver disease. Specifically, affected individuals experience severe itching, yellowing of the skin and whites of the eyes (jaundice), failure to gain weight and grow at the expected rate (failure to thrive), high blood pressure in the vein that supplies blood to the liver (portal hypertension), and an enlarged liver and spleen (hepatosplenomegaly).

Most people with PFIC3 have signs and symptoms related to liver disease only. Signs and symptoms of PFIC3 usually do not appear until later in infancy or early childhood; rarely, people are diagnosed in early adulthood. Liver failure can occur in childhood or adulthood in people with PFIC3.

Progressive familial intrahepatic cholestasis (PFIC) is a disorder that causes progressive liver disease, which typically leads to liver failure. In people with PFIC, liver cells are less able to secrete a digestive fluid called bile. The buildup of bile in liver cells causes liver disease in affected individuals. [from MedlinePlus Genetics]

A rare familial partial lipodystrophy with characteristics of adult onset of distal lipoatrophy with gluteofemoral fat loss, as well as increased fat accumulation in the face and trunk and visceral adiposity. Additional manifestations include diabetes mellitus, atherogenic dyslipidemia, eyelid xanthelasma, arterial hypertension, cardiovascular disease, hepatic steatosis, acanthosis nigricans on axilla and neck, hirsutism, and muscular hypertrophy of the lower limbs. Caused by heterozygous mutation in the PPARG gene on chromosome 3p25. [from SNOMEDCT_US]

Mutation in the CRYGS gene has been identified in multiple types of cataract, which have been described as progressive polymorphic anterior, posterior, peripheral cortical, sutural, and lamellar. [from OMIM]

Mutations in the CRYGD gene have been found to cause multiple types of cataract, which have been described as aculeiform, crystalline aculeiform, crystalline, crystal, frosted, needle-shaped, fasciculiform, congenital cerulean, nonnuclear polymorphic congenital, central nuclear, lamellar, and punctate. Some patients also exhibit microcornea. Because multiple types of cataract are caused by mutation in the CRYGD gene, some of which display intrafamilial variability, several earlier distinct cataract entries in OMIM have been included here. [from OMIM]

Immunodeficiency-27A (IMD27A) results from autosomal recessive (AR) IFNGR1 deficiency. Patients with complete IFNGR1 deficiency have a severe clinical phenotype characterized by early and often fatal mycobacterial infections. The disorder can thus be categorized as a form of mendelian susceptibility to mycobacterial disease (MSMD). Bacillus Calmette-Guerin (BCG) and environmental mycobacteria are the most frequent pathogens, and infection typically begins before the age of 3 years. Plasma from patients with complete AR IFNGR1 deficiency usually contains large amounts of IFNG (147570), and their cells do not respond to IFNG in vitro. In contrast, cells from patients with partial AR IFNGR1 deficiency, which is caused by a specific mutation in IFNGR1, retain residual responses to high IFNG concentrations. Patients with partial AR IFNGR1 deficiency are susceptible to BCG and environmental mycobacteria, but they have a milder clinical disease and better prognosis than patients with complete AR IFNGR1 deficiency. The clinical features of children with complete AR IFNGR1 deficiency are usually more severe than those in individuals with AD IFNGR1 deficiency (IMD27B), and mycobacterial infection often occurs earlier (mean age of 1.3 years vs 13.4 years), with patients having shorter mean disease-free survival. Salmonellosis is present in about 5% of patients with AR or AD IFNGR1 deficiency, and other infections have been reported in single patients (review by Al-Muhsen and Casanova, 2008). [from OMIM]

Gamma-glutamylcysteine synthetase deficiency is 1 of 4 diseases involving enzymes in the gamma-glutamyl cycle (Meister, 1974). The other 3 disorders are glutathione synthetase deficiency (231900), 5-oxoprolinuria, which is a severe or generalized form of glutathione synthetase deficiency (266130), and gamma-glutamyl transpeptidase deficiency (231950). All except gamma-glutamyl transpeptidase deficiency are accompanied by hemolytic anemia (Larsson and Anderson, 2001). The hemolytic anemia caused by mutation in the GCLC gene is here designated congenital nonspherocytic hemolytic anemia-7 (CNSHA7). [from OMIM]

Deficiency of all vitamin K-dependent clotting factors leads to a bleeding tendency that is usually reversed by oral administration of vitamin K. Acquired forms of the disorder can be caused by intestinal malabsorption of vitamin K. Familial multiple coagulation factor deficiency is rare. Clinical symptoms of the disease include episodes of intracranial hemorrhage in the first weeks of life, sometimes leading to a fatal outcome. The pathomechanism is based on a reduced hepatic gamma-carboxylation of glutamic acid residues of all vitamin K-dependent blood coagulation factors, as well as the anticoagulant factors protein C (612283) and protein S (176880). Posttranslational gamma-carboxylation of proteins enables the calcium-dependent attachment of the proteins to the phospholipid bilayer of membranes, an essential prerequisite for blood coagulation. Vitamin K1 acts as a cofactor for the vitamin K-dependent carboxylase in liver microsomes, GGCX. Genetic Heterogeneity of Combined Deficiency of Vitamin K-Dependent Clotting Factors Combined deficiency of vitamin K-dependent clotting factors-2 (VKFCD2; 607473) is caused by mutation in the gene encoding vitamin K epoxide reductase (VKORC1; 608547) on chromosome 16p11. [from OMIM]