Hyperreflexia, and Stereotypy

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

SOURCES: OMIM MENDELIAN

A substantial minority of degenerative dementias, perhaps 10%, lack the distinctive pathologic features that allow subclassification as Alzheimer disease (see {104300}) or other forms of dementia. In perhaps half of these cases of nonspecific dementia, there is a positive family history of dementia, with an apparent autosomal dominant mode of inheritance.See also frontotemporal lobe dementia (FLDEM ), which maps to chromosome 17 and is caused by mutation in the microtubule-associated protein tau gene (MAPT ).

FRONTOTEMPORAL DEMENTIA, CHROMOSOME 3-LINKED; FTD3 Is also known as dem|dementia, familial nonspecific|dmt1

• Hyperreflexia
• Gait disturbance
• Dystonia
• Cerebral atrophy
• Babinski sign

SOURCES: OMIM MESH MENDELIAN

Behavioral variant of frontotemporal dementia (bv-FTD) is a form of frontotemporal dementia (FTD; see this term), characterized by progressive behavioral impairment and a decline in executive function with frontal lobe-predominant atrophy.

BEHAVIORAL VARIANT OF FRONTOTEMPORAL DEMENTIA Is also known as bv-ftd

• Hyperreflexia
• Gait disturbance
• Behavioral abnormality
• Aggressive behavior
• Mental deterioration

SOURCES: ORPHANET MENDELIAN

Spastic tetraplegia, thin corpus callosum, and progressive microcephaly is an autosomal recessive neurodevelopmental disorder characterized by onset of those features and severely impaired global development in early infancy. Most patients are unable to achieve independent walking or speech; some patients have seizures (summary by Srour et al., 2015 and Heimer et al., 2015).

SPASTIC TETRAPLEGIA-THIN CORPUS CALLOSUM-PROGRESSIVE POSTNATAL MICROCEPHALY SYNDROME Is also known as spastic quadriplegia-thin corpus callosum-progressive postnatal microcephaly syndrome|asct1 deficiency

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

SOURCES: OMIM ORPHANET MENDELIAN

EIEE58 is a severe neurodevelopmental disorder characterized by onset of refractory seizures in the first days or months of life. Affected individuals have global developmental delay with intellectual disability, usually with absent speech and inability to walk. Additional features include optic atrophy with poor or absent visual fixation, hypotonia, and spasticity (summary by Hamdan et al., 2017).For a general phenotypic description and a discussion of genetic heterogeneity of EIEE, see EIEE1 (OMIM ).

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

SOURCES: OMIM MENDELIAN

Adenylosuccinate lyase deficiency (ADSL deficiency) is a disorder of purine metabolism characterized by intellectual disability, psychomotor delay and/or regression, seizures, and autistic features.

ADENYLOSUCCINATE LYASE DEFICIENCY Is also known as adenylosuccinate lyase deficiency|adenylosuccinase deficiency|adsl deficiency

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

SOURCES: MESH ORPHANET OMIM MENDELIAN

LESCH-NYHAN SYNDROME; LNS Is also known as hprt deficiency, complete|hypoxanthine guanine phosphoribosyltransferase 1 deficiency|hprt deficiency|hprt1 deficiency

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

SOURCES: OMIM MENDELIAN

Severe intellectual disability and progressive spastic paraplegia is a rare complex spastic paraplegia characterized by an early onset hypotonia that progresses to spasticity, global developmental delay, severe intellectual disability and speech impairment, microcephaly, short stature and dysmorphic features. Patients often become non-ambulatory, and some develop seizures and stereotypic laughter.

SEVERE INTELLECTUAL DISABILITY AND PROGRESSIVE SPASTIC PARAPLEGIA Is also known as ap4 deficiency syndrome|cpsq4, formerly|cerebral palsy, spastic quadriplegic, 4, formerly

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

SOURCES: ORPHANET OMIM MENDELIAN

Leber congenital amaurosis (LCA) is a retinal dystrophy defined by blindness and responses to electrophysiological stimulation (Ganzfeld electroretinogram (ERG)) below threshold, associated with severe visual impairment within the first year of life.

LEBER CONGENITAL AMAUROSIS Is also known as crb|amaurosis congenita of leber i|lca|amaurosis congenita of leber|retinal blindness, congenital

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

SOURCES: OMIM ORPHANET MENDELIAN

Christianson syndrome is a very rare form of syndromic intellectual deficit characterized by microcephaly, severe developmental delay or regression, hypotonia, abnormal movements, and early-onset seizures.

CHRISTIANSON SYNDROME Is also known as x-linked angelman-like syndrome|x-linked intellectual disability, south african type|mental retardation, microcephaly, epilepsy, and ataxia syndrome|x-linked intellectual disability-craniofacial dysmorphism-epilepsy-ophthalmoplegia-cerebellar atrophy synd

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

SOURCES: MESH ORPHANET OMIM MENDELIAN