Autoimmunity, and Distal amyotrophy

Low match PRESYNAPTIC CONGENITAL MYASTHENIC SYNDROMES

Myasthenia gravis is a disease that causes weakness in the muscles under your control. It happens because of a problem in communication between your nerves and muscles. Myasthenia gravis is an autoimmune disease. Your body's own immune system makes antibodies that block or change some of the nerve signals to your muscles. This makes your muscles weaker. Common symptoms are trouble with eye and eyelid movement, facial expression and swallowing. But it can also affect other muscles. The weakness gets worse with activity, and better with rest. There are medicines to help improve nerve-to-muscle messages and make muscles stronger. With treatment, the muscle weakness often gets much better. Other drugs keep your body from making so many abnormal antibodies. There are also treatments which filter abnormal antibodies from the blood or add healthy antibodies from donated blood. Sometimes surgery to take out the thymus gland helps. For some people, myasthenia gravis can go into remission and they do not need medicines. The remission can be temporary or permanent. If you have myasthenia gravis, it is important to follow your treatment plan. If you do, you can expect your life to be normal or close to it. NIH: National Institute of Neurological Disorders and Stroke

• Intellectual disability
• Seizures
• Ataxia
• Nystagmus
• Sensorineural hearing impairment

SOURCES: ORPHANET MENDELIAN

Low match DEHYDRATED HEREDITARY STOMATOCYTOSIS 1 WITH OR WITHOUT PSEUDOHYPERKALEMIA AND/OR PERINATAL EDEMA; DHS1

Dehydrated hereditary stomatocytosis (DHS), also known as hereditary xerocytosis, is an autosomal dominant hemolytic anemia characterized by primary erythrocyte dehydration. DHS erythrocytes exhibit decreased total cation and potassium content that are not accompanied by a proportional net gain of sodium and water. DHS patients typically exhibit mild to moderate compensated hemolytic anemia, with an increased erythrocyte mean corpuscular hemoglobin concentration and a decreased osmotic fragility, both of which reflect cellular dehydration (summary by Zarychanski et al., 2012). Patients may also show perinatal edema and pseudohyperkalemia due to loss of K+ from red cells stored at room temperature. A minor proportion of red cells appear as stomatocytes on blood films. Complications such as splenomegaly and cholelithiasis, resulting from increased red cell trapping in the spleen and elevated bilirubin levels, respectively, may occur. The course of DHS is frequently associated with iron overload, which may lead to hepatosiderosis (summary by Albuisson et al., 2013).Dehydrated red blood cells, including those from hereditary xerocytosis patients, show delayed infection rates to Plasmodium in vitro, suggesting a potential protective mechanism against malaria (Tiffert et al., 2005). A polymorphism in PIEZO1 that is enriched in populations of African descent and results in xerocytosis conferred resistance to Plasmodium infection in vitro (see {611184.0016}).The 'leaky red blood cells' in familial pseudohyperkalemia show a temperature-dependent loss of potassium when stored at room temperature, manifesting as apparent hyperkalemia. The red blood cells show a reduced life span in vivo, but there is no frank hemolysis. Studies of cation content and transport show a marginal increase in permeability at 37 degrees C and a degree of cellular dehydration, qualitatively similar to the changes seen in dehydrated hereditary stomatocytosis. Physiologic studies show that the passive leak of potassium has an abnormal temperature dependence, such that the leak is less sensitive to temperature than that in normal cells (summary by Iolascon et al., 1999).Carella et al. (2004) noted that 3 clinical forms of pseudohyperkalemia unassociated with hematologic manifestations, based predominantly on the leak-temperature dependence curve, had been reported: (1) pseudohyperkalemia Edinburgh, in which the curve has a shallow slope; (2) pseudohyperkalemia Chiswick or Falkirk (see {609153}), in which the curve is shouldered; and (3) pseudohyperkalemia Cardiff (see {609153}), in which the temperature dependence of the leak shows a 'U-shaped' profile with a minimum at 23 degrees C. Gore et al. (2004) stated that potassium-flux temperature profiles are consistent both from year to year in an individual as well as consistent within affected members of a pedigree. Genetic Heterogeneity of Hereditary StomatocytosisDehydrated hereditary stomatocytosis-2 (DHS2 ) is caused by mutation in the KCNN4 gene (OMIM ) on chromosome 19q13. Another form of stomatocytosis, involving familial pseudohyperkalemia with minimal hematologic abnormalities (PSHK2 ), is caused by mutation in the ABCB6 gene (OMIM ) on chromosome 2q35. Cryohydrocytosis (CHC ) is caused by mutation in the SLC4A1 gene (OMIM ) on chromosome 17q21, and stomatin-deficient cryohydrocytosis with neurologic defects (SDCHCN ) is caused by mutation in the SLC2A1 gene (OMIM ) on chromosome 1p34. An overhydrated form of hereditary stomatocytosis (OHST ) is caused by mutation in the RHAG gene (OMIM ) on chromosome 6p12.See {137280} for a discussion of the association of familial stomatocytosis and hypertrophic gastritis in the dog, an autosomal recessive syndrome. ReviewsDelaunay (2004) reviewed genetic disorders of red cell membrane permeability to monovalent cations, noting 'inevitable' overlap between entities based on clinical phenotype.Bruce (2009) provided a review of hereditary stomatocytosis and cation-leaky red cells, stating that consistent features include hemolytic anemia, a monovalent cation leak, and changes in red cell morphology that appear to follow a continuum, from normal discocyte to stomatocyte to echinocyte in DHS, and from discocyte to stomatocyte to spherocyte to fragmentation in OHST. Bruce (2009) suggested that the underlying pathologic mechanism might involve misfolded mutant proteins that escape the quality control system of the cell and reach the red cell membrane, where they disrupt the red cell membrane structure and cause a cation leak that alters the hydration of the red cell, thereby changing the morphology and viability of the cell.King and Zanella (2013) provided an overview of 2 groups of nonimmune hereditary red cell membrane disorders caused by defects in membrane proteins located in distinct layers of the red cell membrane: red cell cytoskeleton disorders, including hereditary spherocytosis (see {182900}), hereditary elliptocytosis (see {611804}), and hereditary pyropoikilocytosis (OMIM ); and cation permeability disorders of the red cell membrane, or hereditary stomatocytoses, including DHS, OHST, CHC, and PSHK. The authors noted that because there is no specific screening test for the hereditary stomatocytoses, a preliminary diagnosis is based on the presence of a compensated hemolytic anemia, macrocytosis, and a temperature- or time-dependent pseudohyperkalemia in some patients. King et al. (2015) reported the International Council for Standardization in Haematology (ICSH) guidelines for laboratory diagnosis of nonimmune hereditary red cell membrane disorders.

DEHYDRATED HEREDITARY STOMATOCYTOSIS 1 WITH OR WITHOUT PSEUDOHYPERKALEMIA AND/OR PERINATAL EDEMA; DHS1 Is also known as pseudohyperkalemia, familial, 1, due to red cell leak|pshk1|dhs|dehydrated hereditary stomatocytosis|xerocytosis, hereditary|desiccytosis, hereditary|pseudohyperkalemia edinburgh

• Anemia
• Hepatomegaly
• Fever
• Fatigue
• Edema

SOURCES: OMIM MENDELIAN

Low match LYSINURIC PROTEIN INTOLERANCE

Lysinuric protein intolerance (LPI) is a very rare inherited multisystem condition caused by distrubance in amino acid metabolism.

LYSINURIC PROTEIN INTOLERANCE Is also known as lpi|hyperdibasic aminoaciduria type 2|dibasic amino aciduria ii

• Intellectual disability
• Short stature
• Generalized hypotonia
• Failure to thrive
• Muscle weakness

SOURCES: OMIM MESH ORPHANET MENDELIAN

Low match PRIMARY SCLEROSING CHOLANGITIS

Primary sclerosing cholangitis (PSC) is a rare, slowly progressive liver disease characterized by inflammation and destruction of the intra- and/or extra-hepatic bile ducts that lead to cholestasis, liver fibrosis, liver cirrhosis and ultimately liver failure.

PRIMARY SCLEROSING CHOLANGITIS Is also known as psc

• Pain
• Hypertension
• Hepatomegaly
• Fever
• Fatigue

SOURCES: ORPHANET OMIM MENDELIAN

Low match BANNAYAN-RILEY-RUVALCABA SYNDROME

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare congenital disorder characterized by hamartomatous intestinal polyposis, lipomas, macrocephaly and genital lentiginosis.

BANNAYAN-RILEY-RUVALCABA SYNDROME Is also known as brrs|myhre-riley-smith syndrome

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Scoliosis

SOURCES: ORPHANET MENDELIAN

Low match NIJMEGEN BREAKAGE SYNDROME

Nijmegen breakage syndrome is a rare genetic disease presenting at birth with microcephaly, dysmorphic facial features, becoming more noticeable with age, growth delay, and later-onset complications such as malignancies and infections.

NIJMEGEN BREAKAGE SYNDROME Is also known as microcephaly-immunodeficiency-lymphoreticuloma syndrome|ataxia-telangiectasia variant v1|microcephaly with normal intelligence, immunodeficiency, and lymphoreticular malignancies|at-v1|berlin breakage syndrome|ataxia-telangiectasia, variant 1|seemanova sy

• Intellectual disability
• Global developmental delay
• Short stature
• Microcephaly
• Ataxia

SOURCES: ORPHANET OMIM MESH MENDELIAN

Low match AUTOSOMAL DOMINANT CHARCOT-MARIE-TOOTH DISEASE TYPE 2K

Autosomal dominant Charcot-Marie-Tooth disease, type 2K (CMT2K) is an axonal CMT peripheral sensorimotor polyneuropathy.

AUTOSOMAL DOMINANT CHARCOT-MARIE-TOOTH DISEASE TYPE 2K Is also known as cmt2k

• Motor delay
• Skeletal muscle atrophy
• Gait disturbance
• Arrhythmia
• Proximal muscle weakness

SOURCES: ORPHANET MENDELIAN

Low match LIPODYSTROPHY, CONGENITAL GENERALIZED, TYPE 1; CGL1

Congenital generalized lipodystrophy (CGL), or Berardinelli-Seip syndrome, is a rare autosomal recessive disease characterized by a near absence of adipose tissue from birth or early infancy and severe insulin resistance. Other clinical and biologic features include acanthosis nigricans, muscular hypertrophy, hepatomegaly, altered glucose tolerance or diabetes mellitus, and hypertriglyceridemia (Garg, 2004). Genetic Heterogeneity of Congenital Generalized LipodystrophyCongenital generalized lipodystrophy type 2 (OMIM ) is caused by mutation in the BSCL2 gene (OMIM ). Congenital generalized lipodystrophy type 3 (OMIM ) is caused by mutation in the CAV1 gene (OMIM ). Congenital generalized lipodystrophy type 4 (OMIM ) is caused by mutation in the PTRF gene (OMIM ).

LIPODYSTROPHY, CONGENITAL GENERALIZED, TYPE 1; CGL1 Is also known as berardinelli-seip congenital lipodystrophy, type 1|lipodystrophy, berardinelli-seip congenital, type 1|brunzell syndrome, agpat2-related|bscl1

• Intellectual disability
• Cognitive impairment
• Hypertension
• Peripheral neuropathy
• Hepatomegaly

SOURCES: OMIM MENDELIAN

Low match AUTOSOMAL DOMINANT INTERMEDIATE CHARCOT-MARIE-TOOTH DISEASE TYPE C

Autosomal dominant intermediate Charcot-Marie-Tooth disease type C is a rare hereditary motor and sensory neuropathy characterized by intermediate motor median nerve conduction velocities (usually between 25 and 60 m/s). It presents with moderately severe, slowly progressive usual clinical features of Charcot-Marie-Tooth disease (muscle weakness and atrophy of the distal extremities, distal sensory loss, reduced or absent deep tendon reflexes, feet deformities, extensor digitorum brevis atrophy). Findings in nerve biopsies include age-dependent axonal degeneration, reduced number of large myelinated fibres, segmental remyelination, and no onion bulbs.

AUTOSOMAL DOMINANT INTERMEDIATE CHARCOT-MARIE-TOOTH DISEASE TYPE C Is also known as charcot-marie-tooth neuropathy, dominant intermediate c|di-cmtc|cmtdic

• Muscle weakness
• Skeletal muscle atrophy
• Distal muscle weakness
• Abnormality of the foot
• Distal amyotrophy

SOURCES: MESH OMIM ORPHANET MENDELIAN

Low match NONAKA MYOPATHY; NM

NONAKA MYOPATHY; NM Is also known as myopathy, distal, with or without rimmed vacuoles|gne myopathy|inclusion body myopathy 2, autosomal recessive, formerly|ibm2, formerly|hibm|nonaka distal myopathy|inclusion body myopathy, quadriceps-sparing|qsm|inclusion body myopathy, hereditary, autosom

• Ataxia
• Muscle weakness
• Gait disturbance
• Myopathy
• Elevated serum creatine phosphokinase

SOURCES: OMIM MENDELIAN