Muscular hypotonia, and Abnormality of the cerebral white matter

Combined oxidative phosphorylation defect type 21 is a rare mitochondrial disease characterized by axial hypotonia with limb hypertonia, developmental delay, hyperlactatemia, central nervous system anomalies visible on magnetic resonance imaging (e.g. corpus callosum hypoplasia, lesions of the globus pallidus) and multiple deficiency of the mitochondrial respiratory chain complexes in muscle tissue, but not in fibroblasts or liver.

COMBINED OXIDATIVE PHOSPHORYLATION DEFECT TYPE 21 Is also known as coxpd21

• Global developmental delay
• Generalized hypotonia
• Hypoplasia of the corpus callosum
• Hypertonia
• Muscular hypotonia of the trunk

SOURCES: ORPHANET OMIM MENDELIAN

MTDPS12A is characterized by severe hypotonia due to mitochondrial dysfunction apparent at birth. Affected infants have respiratory insufficiency requiring mechanical ventilation and have poor or no motor development. Many die in infancy, and those that survive have profound hypotonia with significant muscle weakness and inability to walk independently. Some patients develop hypertrophic cardiomyopathy. Muscle samples show mtDNA depletion and severe combined mitochondrial respiratory chain deficiencies (summary by Thompson et al., 2016).For a discussion of genetic heterogeneity of mtDNA depletion syndromes, see MTDPS1 (OMIM ).

• Seizures
• Generalized hypotonia
• Muscle weakness
• Respiratory insufficiency
• Cardiomyopathy

SOURCES: OMIM MENDELIAN

Foetal methylmercury syndrome is characterised by a group of symptoms that may be observed in a foetus or newborn when the mother was exposed during pregnancy to excessive amounts of methylmercury.

FETAL METHYLMERCURY SYNDROME Is also known as methyl mercury antenatal infection|minamata disease

• Short stature
• Hearing impairment
• Microcephaly
• Muscular hypotonia
• Visual impairment

SOURCES: MESH ORPHANET MENDELIAN

Pyruvate dehydrogenase E1-beta deficiency is an extremely rare form of pyruvate dehydrogenase deficiency (PDHD, see this term) characterized by severe lactic acidosis, developmental delay and hypotonia.

PYRUVATE DEHYDROGENASE E1-BETA DEFICIENCY Is also known as pdhbd|pyruvate dehydrogenase complex e1 component subunit beta deficiency

• Generalized hypotonia
• Agenesis of corpus callosum
• Acidosis
• Lactic acidosis
• Metabolic acidosis

SOURCES: OMIM ORPHANET MESH MENDELIAN

Autosomal dominant remitting MLC2B is characterized by infantile-onset of macrocephaly and mildly delayed motor development associated with white matter abnormalities on brain MRI that improve with age. As children, some patients have mild residual hypotonia or clumsiness, but otherwise have no residual motor abnormalities. About 40% of patients have mental retardation (summary by van der Knaap et al., 2010 and Lopez-Hernandez et al., 2011).Homozygous or compound heterozygous mutations in the HEPACAM gene can cause a more severe and progressive disorder associated with ataxia, spasticity, and mental retardation (MLC2A ).For a discussion of genetic heterogeneity of megalencephalic leukoencephalopathy with subcortical cysts, see MLC1 (OMIM ).

• Intellectual disability
• Generalized hypotonia
• Ataxia
• Spasticity
• Motor delay

SOURCES: OMIM MENDELIAN

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Delayed speech and language development

SOURCES: OMIM MENDELIAN

• Global developmental delay
• Generalized hypotonia
• Ataxia
• Nystagmus
• Strabismus

SOURCES: OMIM MENDELIAN

• Seizures
• Global developmental delay
• Generalized hypotonia
• Ventriculomegaly
• Hypoplasia of the corpus callosum

SOURCES: OMIM MENDELIAN

• Seizures
• Global developmental delay
• Generalized hypotonia
• Ataxia
• Visual impairment

SOURCES: OMIM MENDELIAN

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

SOURCES: OMIM MENDELIAN