Cardiomyopathy, and Aggressive behavior

NEMMLAS is an autosomal recessive multisystemic disorder characterized by delayed psychomotor development, intellectual disability, and abnormal motor function, including hypotonia, dystonia, ataxia, and spasticity. Patient tissues may show deficiencies in one or more of the mitochondrial oxidative phosphorylation (OXPHOS) enzymes, but this is not a constant finding (summary by Wortmann et al., 2017).

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Ataxia

SOURCES: OMIM MENDELIAN

HSD10 mitochondrial disease most commonly presents as an X-linked neurodegenerative disorder with highly variable severity and age at onset ranging from the neonatal period to early childhood. The features are usually multisystemic, consistent with mitochondrial dysfunction. Some affected males have a severe infantile form associated with cardiomyopathy that may result in death in early childhood, whereas other rare patients may have juvenile onset or even atypical presentations with normal neurologic development. More severely affected males show developmental regression in infancy or early childhood, often associated with early-onset intractable seizures, progressive choreoathetosis and spastic tetraplegia, optic atrophy or retinal degeneration resulting in visual loss, and mental retardation. Heterozygous females may show non-progressive developmental delay and intellectual disability, but may also be clinically normal. Although the diagnosis can be aided by the observation of increased urinary levels of metabolites of isoleucine breakdown (2-methyl-3 hydroxybutyrate and tiglylglycine), there is not a correlation between these laboratory features and the phenotype. In addition, patients do not develop severe metabolic crises in the neonatal period as observed in other organic acidurias, but may show persistent lactic acidosis, most likely reflecting mitochondrial dysfunction (summary by Rauschenberger et al., 2010; review by Zschocke, 2012).In a review of the disorder, Zschocke (2012) noted that although this disorder was originally thought to be an inborn error of branched-chain fatty acid and isoleucine metabolism resulting from decreased HSD17B10 dehydrogenase activity (HSD17B10 'deficiency'), subsequent studies have shown that the HSD17B10 gene product has additional functions and also acts as a component of the mitochondrial RNase P holoenzyme, which is involved in mitochondrial tRNA processing and maturation and ultimately mitochondrial protein synthesis. The multisystemic features of HSD10MD most likely result from the adverse effect of HSD17B10 mutations on mitochondrial function, rather than from the effects on the dehydrogenase activity (see PATHOGENESIS below).

HSD10 MITOCHONDRIAL DISEASE; HSD10MD Is also known as hsd17b10 deficiency|mhbd deficiency|2-methyl-3-hydroxybutyryl-coa dehydrogenase deficiency|camr|mental retardation with chorioathetosis and abnormal behavior|mental retardation, x-linked, syndromic 10|17-beta-hydroxysteroid dehydrogenase x deficiency|chor

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment

SOURCES: ORPHANET OMIM MENDELIAN

The mucopolysaccharidoses are a family of lysosomal storage diseases caused by deficiencies of enzymes required for the catabolism of glycosaminoglycans. The defects result in accumulation of excessive intralysosomal glycosoaminoglycans (mucopolysaccharides) in various tissues, causing distended lysosomes to accumulate in the cell and interfere with cell function. Multiple types have been described (Mok et al., 2003).

MUCOPOLYSACCHARIDOSIS, TYPE IIID; MPS3D Is also known as sanfilippo syndrome d|mps iiid|n-acetylglucosamine-6-sulfatase deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Hearing impairment
• Low-set ears

SOURCES: OMIM MENDELIAN

Sanfilippo syndrome B is an autosomal recessive lysosomal storage disorder characterized by the accumulation of heparan sulfate. Clinically, patients have progressive neurodegeneration, behavioral problems, mild skeletal changes, and shortened life span. The clinical severity ranges from mild to severe (Chinen et al., 2005).For a phenotypic description and a discussion of genetic heterogeneity of Sanfilippo syndrome, or mucopolysaccharidosis III, see MPS IIIA (OMIM ).

MUCOPOLYSACCHARIDOSIS, TYPE IIIB; MPS3B Is also known as sanfilippo syndrome b|mps iiib|n-acetyl-alpha-d-glucosaminidase deficiency|naglu deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Hearing impairment
• Ataxia

SOURCES: OMIM MENDELIAN

Chorea-acanthocytosis (ChAc) is a form of neuroacanthocytosis (see this term) and is characterized clinically by a Huntington disease-like phenotype with progressive neurological symptoms including movement disorders, psychiatric manifestations and cognitive disturbances.

CHOREOACANTHOCYTOSIS Is also known as neuroacanthocytosis|chorea-acanthocytosis|chac|levine-critchley syndrome|acanthocytosis with neurologic disorder

• Seizures
• Short stature
• Ataxia
• Nystagmus
• Muscle weakness

SOURCES: ORPHANET OMIM MENDELIAN

Wolfram syndrome-1 is a rare and severe autosomal recessive neurodegenerative disease characterized by diabetes mellitus, optic atrophy, diabetes insipidus, and deafness (DIDMOAD). Additional clinical features may include renal abnormalities, ataxia, dementia or mental retardation, and diverse psychiatric illnesses. The minimal diagnostic criteria for Wolfram syndrome are optic atrophy and diabetes mellitus of juvenile onset. Hearing impairment in Wolfram syndrome is typically progressive and mainly affects the higher frequencies, but a small fraction of affected individuals have congenital deafness (summary by Rendtorff et al., 2011).Autosomal dominant mutations in the WFS1 gene have been found to cause low-frequency nonsyndromic deafness (OMIM ) as well as a Wolfram syndrome-like phenotype (OMIM ) in which affected individuals have hearing impairment with diabetes mellitus and/or optic atrophy. Genetic Heterogeneity of Wolfram SyndromeWolfram syndrome-2 (WFS2 ) is caused by mutation in the CISD2 gene (OMIM ) on chromosome 4q24.

WOLFRAM SYNDROME 1; WFS1 Is also known as diabetes insipidus and mellitus with optic atrophy and deafness|wfs|didmoad

• Intellectual disability
• Seizures
• Hearing impairment
• Ataxia
• Growth delay

SOURCES: OMIM MENDELIAN

The Cornelia de Lange syndrome (CDLS) is a multisystem malformation syndrome recognized primarily on the basis of characteristic facial dysmorphism, including low anterior hairline, arched eyebrows, synophrys, anteverted nares, maxillary prognathism, long philtrum, thin lips, and 'carp' mouth, in association with prenatal and postnatal growth retardation, mental retardation and, in many cases, upper limb anomalies. However, there is wide clinical variability in this disorder, with milder phenotypes that may be difficult to ascertain on the basis of physical features (summary by Rohatgi et al., 2010).Boyle et al. (2015) provided a detailed review of CDLS, including clinical features, diagnosis, and genetic counseling. Genetic Heterogeneity of Cornelia de Lange SyndromeAbout 50 to 60% of the cases of CDLS are due to mutation in the NIPBL gene (Musio et al., 2006; Rohatgi et al., 2010).One X-linked form of CDLS (CDLS2 ) is caused by mutation in the SMC1A gene (OMIM ), which accounts for about 5% of cases. Two milder variants of Cornelia de Lange syndrome have been identified: CDLS3 (OMIM ), caused by mutation in the SMC3 gene (OMIM ), and CDLS4 (OMIM ), caused by mutation in the RAD21 gene (OMIM ). All 4 genes, NIPBL, SMC1A, SMC3, and RAD21, encode components of the cohesin complex. Another X-linked form, CDLS5 (OMIM ), is caused by mutation in the HDAC8 gene (OMIM ), the vertebrate histone deacetylase of SMC3.

CORNELIA DE LANGE SYNDROME 1; CDLS1 Is also known as typus degenerativus amstelodamensis|brachmann-de lange syndrome|cdl|de lange syndrome|cdls|bdls

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: OMIM MENDELIAN

1p36 deletion syndrome is a chromosomal anomaly characterized by distinctive facial dysmorphic features, hypotonia, developmental delay, intellectual disability, seizures, heart defects, hearing impairment and prenatal onset growth deficiency.

1P36 DELETION SYNDROME Is also known as del(1)(p36)|monosomy 1p36|monosomy 1pter|deletion 1pter|deletion 1p36|monosomy 1p36 syndrome|subtelomeric 1p36 deletion

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: ORPHANET OMIM MESH MENDELIAN

Cardiofaciocutaneous (CFC) syndrome is a RASopathy characterized by craniofacial dysmorphology, congenital heart disease, dermatological abnormalities (most commonly hyperkeratotic skin and sparse, curly hair), growth retardation and intellectual disability.

CARDIOFACIOCUTANEOUS SYNDROME Is also known as cfcs|cfc syndrome

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: ORPHANET OMIM MENDELIAN

Macrocephaly-intellectual disability-left ventricular non compaction syndrome is a rare, genetic, syndromic intellectual disability characterized by motor and cognitive developmental delay with language impairment, macrocephaly, hypotonia, dysmorphic facial features (including long face, slanting palpebral fissures and prominent, flattened nose) and left ventricular noncompaction cardiomyopathy. Patients also present skeletal abnormalities (e.g. scoliosis, finger clinodactyly, pes planus), slender build and shy behavior. Strabismus and various neurological signs (including ataxia, tremor and hyperreflexia) may be associated, as well as epilepsy, autism and MRI findings showing a small cerebellum and abnormalities of the corpus callosum. A phenotypic variant with no cardiac involvement has been reported.

MACROCEPHALY-INTELLECTUAL DISABILITY-LEFT VENTRICULAR NON COMPACTION SYNDROME Is also known as mrxsml|mental retardation, x-linked, syndromic, mircsof-langouet type

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Scoliosis

SOURCES: OMIM ORPHANET MENDELIAN