Microcephaly, and Gliosis

X-linked intellectual disability-short stature-overweight syndrome is a multiple congenital anomalies syndrome characterized by borderline to severe intellectual disability, speech delay, short stature, elevated body mass index, a pattern of truncal obesity (reported in older males), and variable neurologic features (e.g. hypotonia, tremors, gait disturbances, behavioral problems, and seizure disorders). Less common manifestations include microcephaly, microorchidism and/or microphallus. Dysmorphic features have been reported in some patients but no consitent pattern has been noted.

X-LINKED INTELLECTUAL DISABILITY-SHORT STATURE-OVERWEIGHT SYNDROME Is also known as mental retardation, x-linked 35|mrx35

• Intellectual disability
• Seizures
• Short stature
• Generalized hypotonia
• Microcephaly

SOURCES: OMIM ORPHANET MENDELIAN

Pontocerebellar hypoplasia type 4 (PCH4) is a very rare form of PCH (see this term), characterized by prenatal onset of polyhydramnios and contractures followed by hypertonia, severe clonus, primary hypoventilation leading to an early postnatal death.

PONTOCEREBELLAR HYPOPLASIA TYPE 4 Is also known as fatal infantile encephalopathy with olivopontocerebellar hypoplasia|olivopontocerebellar hypoplasia|encephalopathy, fatal infantile, with olivopontocerebellar hypoplasia|pch4

• Seizures
• Microcephaly
• Spasticity
• Flexion contracture
• Cerebellar atrophy

SOURCES: ORPHANET MESH OMIM MENDELIAN

• Seizures
• Generalized hypotonia
• Microcephaly
• Spasticity
• Respiratory distress

SOURCES: OMIM MENDELIAN

Microcephalic primordial dwarfism due to ZNF335 deficiency is characterized by severe antenatal microencephaly, simplified gyration, agenesis of the corpus callosum, absence of basal ganglia (very rare), pontocerebellar atrophy and involvement of the white matter with secondary cerebral atrophy. Congenital cataract, choanal atresia, multiple arthrogryposis and spastic tetraparesis can occur.

MICROCEPHALIC PRIMORDIAL DWARFISM DUE TO ZNF335 DEFICIENCY Is also known as microcephalic primordial dwarfism, walsh type

• Microcephaly
• Micrognathia
• Cataract
• Spasticity
• Flexion contracture

SOURCES: OMIM ORPHANET MENDELIAN

Early infantile epileptic encephalopathy-14 is a severe neurologic disorder characterized by onset in the first 6 months of life of refractory focal seizures and arrest of psychomotor development. Ictal EEG shows discharges that arise randomly from various areas of both hemispheres and migrate from one brain region to another. The disorder presents as 'malignant migrating partial seizures of infancy' (MMPSI), a clinical designation (summary by Barcia et al., 2012).For a general phenotypic description and a discussion of genetic heterogeneity of EIEE, see EIEE1 (OMIM ).

MALIGNANT MIGRATING PARTIAL SEIZURES OF INFANCY Is also known as mmpei|malignant migrating partial epilepsy of infancy|mmpsi|migrating partial epilepsy of infancy|mpsi|mpei|migrating partial seizures of infancy

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

SOURCES: OMIM ORPHANET MENDELIAN

Lethal left ventricular non-compaction-seizures-hypotonia-cataract-developmental delay syndrome is rare, genetic, neurometabolic disease characterized by global developmental delay, severe hypotonia, seizures, cataracts, cardiomyopathy (including left or bi-ventricular hypertrophy, dilated cardiomyopathy) and left ventricular non-compaction, typically resulting in infantile or early-childhood death. Patients usually present metabolic lactic acidosis, failure to thrive, head lag, respiratory problems and decrease in respiratory chain complex activity. Highly variable cerebral abnormalities have been reported and include microcephaly, prominent extra-axial cerebrospinal fluid spaces, diffuse neuronal loss and cortical/white matter gliosis.

• Seizures
• Global developmental delay
• Generalized hypotonia
• Microcephaly
• Failure to thrive

SOURCES: OMIM ORPHANET MENDELIAN

Pontocerebellar hypoplasia (PCH) represents a heterogeneous group of disorders characterized by an abnormally small cerebellum and brainstem. PCH type 2 is characterized by progressive microcephaly from birth combined with extrapyramidal dyskinesia and chorea, epilepsy, and normal spinal cord findings (Barth, 1993).For a phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (OMIM ). Genetic Heterogeneity of Pontocerebellar Hypoplasia Type 2PCH2B (OMIM ) is caused by mutation in the TSEN2 gene (OMIM ) on chromosome 3p25, and PCH2C (OMIM ) is caused by mutation in the TSEN34 gene (OMIM ) on chromosome 19q13. PCH2D (OMIM ) is caused by mutation in the SEPSECS gene (OMIM ) on chromosome 4p15. PCH2E (OMIM ) is caused by mutation in the VPS53 gene (OMIM ) on chromosome 17p13. PCH2F (OMIM ) is caused by mutation in the TSEN15 gene (OMIM ) on chromosome 1q25. The TSEN2 and TSEN34 genes encode catalytic subunits of the tRNA splicing endonuclease, whereas the TSEN54 gene encodes a noncatalytic subunit. The SEPSECS gene is also involved in tRNA processing.

PONTOCEREBELLAR HYPOPLASIA, TYPE 2A; PCH2A Is also known as pch2|volendam neurodegenerative disease|pontocerebellar hypoplasia with progressive cerebral atrophy

• Seizures
• Microcephaly
• Failure to thrive
• Flexion contracture
• Feeding difficulties

SOURCES: OMIM MENDELIAN

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive muscular paralysis reflecting degeneration of motor neurons in the primary motor cortex, corticospinal tracts, brainstem and spinal cord.

AMYOTROPHIC LATERAL SCLEROSIS Is also known as als|amyotrophic lateral sclerosis 1, autosomal dominant|fals|lou gehrig disease|charcot disease|amyotrophic lateral sclerosis 1, familial

• Microcephaly
• Muscle weakness
• Pain
• Cataract
• Spasticity

SOURCES: OMIM MESH ORPHANET MENDELIAN

Combined oxidative phosphorylation defect type 24 is a rare mitochondrial oxidative phosphorylation disorder characterized by variable phenotype, including developmental delay with psychomotor regression, intellectual disability, epilepsy, Leigh syndrome, non-syndromic hearing loss, visual impairment and severe myopathy. Decreased activity of mitochondrial respiratory complexes and lactic acidosis are common findings, and diffuse cerebral atrophy may be associated.

COMBINED OXIDATIVE PHOSPHORYLATION DEFECT TYPE 24 Is also known as coxpd24

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

SOURCES: OMIM ORPHANET MENDELIAN

Combined oxidative phosphorylation deficiency-32 is an autosomal recessive neurodegenerative disorder characterized by onset of delayed psychomotor development and developmental regression in infancy. Affected individuals have multiple variable symptoms, including poor or absent speech, inability to walk, and abnormal movements. Brain imaging shows T2-weighted abnormalities in the basal ganglia and brainstem consistent with Leigh syndrome (OMIM ). Patient cells showed decreased activities of mitochondrial respiratory chain complexes, I, III, and IV, as well as impaired mitochondrial translation (summary by Lake et al., 2017).For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (OMIM ).

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

SOURCES: OMIM MENDELIAN