Hypertelorism, and Focal seizures, afebril

TREMOR-ATAXIA-CENTRAL HYPOMYELINATION SYNDROME Is also known as tach syndrome

• Global developmental delay
• Short stature
• Ataxia
• Nystagmus
• Spasticity

SOURCES: ORPHANET MENDELIAN

Mucopolysaccharidosis type 2 (MPS2, see this term), severe form (MPS2S), is associated with a massive accumulation of glycosaminoglycans and a wide variety of symptoms including a rapidly progressive cognitive decline; it is most often fatal in the second or third decade.

MUCOPOLYSACCHARIDOSIS TYPE 2, SEVERE FORM Is also known as mucopolysaccharidosis type ii, severe form|mps2a|iduronate 2-sulfatase deficiency type a|mucopolysaccharidosis type 2a|hunter syndrome type a|mpsiia|mucopolysaccharidosis type iia

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Hearing impairment

SOURCES: ORPHANET MENDELIAN

Intellectual developmental disorder with neuropsychiatric features is an autosomal recessive disorder characterized by moderate intellectual disability, relatively mild seizures, and neuropsychiatric abnormalities, such as anxiety, obsessive-compulsive behavior, and autistic features. Mild facial dysmorphic features may also be present (summary by Srour et al., 2017).

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

SOURCES: OMIM MENDELIAN

Spastic quadriplegia-52 is an autosomal recessive neurodevelopmental disorder characterized by neonatal hypotonia that progresses to hypertonia and spasticity and severe mental retardation with poor or absent speech development (summary by Abou Jamra et al., 2011). Some patients may have seizures (Hardies et al., 2015).

SPASTIC PARAPLEGIA 52, AUTOSOMAL RECESSIVE; SPG52 Is also known as cerebral palsy, spastic quadriplegic, 6, formerly|cpsq6, formerly

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

SOURCES: OMIM MENDELIAN

MRD13 is an autosomal dominant form of mental retardation associated with variable neuronal migration defects resulting in cortical malformations. More variable features include early-onset seizures and mild dysmorphic features. Some patients may also show signs of peripheral neuropathy, such as abnormal gait, hyporeflexia, and foot deformities (summary by Willemsen et al., 2012 and Poirier et al., 2013).

MENTAL RETARDATION, AUTOSOMAL DOMINANT 13; MRD13 Is also known as mental retardation, autosomal dominant 13, with neuronal migration defects

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

SOURCES: OMIM MENDELIAN

Spastic paraplegia-severe developmental delay-epilepsy syndrome is a rare, genetic, complex spastic paraplegia disorder characterized by an infantile-onset of psychomotor developmental delay with severe intellectual disability and poor speech acquisition, associated with seizures (mostly myoclonic), muscular hypotonia which may be noted at birth, and slowly progressive spasticity in the lower limbs leading to severe gait disturbances. Ocular abnormalities and incontinence are commonly associated. Other symptoms may include verbal dyspraxia, hypogenitalism, macrocephaly and sensorineural hearing loss, as well as dystonic movements and ataxia with upper limb involvement.

SPASTIC PARAPLEGIA-SEVERE DEVELOPMENTAL DELAY-EPILEPSY SYNDROME Is also known as spastic paraplegia-psychomotor retardation-seizures syndrome|spprs syndrome

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

SOURCES: OMIM ORPHANET MENDELIAN

Non-progressive cerebellar ataxia with intellectual deficit is a rare subtype of autosomal dominant cerebellar ataxia type 1 (ADCA type 1; see this term) characterized by the onset in infancy of cerebellar ataxia, neonatal hypotonia (in some), mild developmental delay and, in later life, intellectual disability. Less common features include dysarthria, dysmetria and dysmorphic facial features (long face, bulbous nose long philtrum, thick lower lip and pointed chin).

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

SOURCES: OMIM ORPHANET MENDELIAN

Periventricular nodular heterotopia (PNH) is a brain malformation, due to abnormal neuronal migration, in which a subset of neurons fails to migrate into the developing cerebral cortex and remains as nodules that line the ventricular surface. Classical PNH is a rare X-linked dominant disorder far more frequent in females who present normal intelligence to borderline intellectual deficit, epilepsy of variable severity and extra-central nervous system signs, especially cardiovascular defects or coagulopathy. The disorder is generally associated with prenatal lethality in males.

PERIVENTRICULAR NODULAR HETEROTOPIA Is also known as heterotopia, periventricular, ehlers-danlos variant|periventricular nodular heterotopia 4, formerly|heterotopia, familial nodular|heterotopia, periventricular, x-linked dominant|pvnh4, formerly|nhbp|nodular heterotopia, bilateral periventricular|bpnh

• Intellectual disability
• Seizures
• Global developmental delay
• Microcephaly
• Hypertelorism

SOURCES: OMIM ORPHANET MENDELIAN

Autosomal recessive cutis laxa type IID (ARCL2D) is characterized by generalized skin wrinkling with sparse subcutaneous fat and dysmorphic progeroid facial features. Most patients also exhibit severe hypotonia as well as cardiovascular and neurologic involvement (summary by Van Damme et al., 2017).For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see ARCL1A (OMIM ).

• Seizures
• Generalized hypotonia
• Microcephaly
• Hypertelorism
• Failure to thrive

SOURCES: ORPHANET OMIM MENDELIAN

POLYHYDRAMNIOS-MEGALENCEPHALY-SYMPTOMATIC EPILEPSY SYNDROME Is also known as pmse syndrome

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

SOURCES: MESH OMIM ORPHANET MENDELIAN