Ataxia, and Hypertelorism

Medium match JOUBERT SYNDROME 32; JBTS32

JBTS32 is an autosomal recessive developmental disorder characterized by delayed psychomotor development, intellectual disability, dysmorphic facial features, and postaxial polydactyly. Brain imaging shows cerebellar abnormalities consistent with the molar tooth sign (MTS) (summary by De Mori et al., 2017).For discussion of genetic heterogeneity of Joubert syndrome, see JBTS1 (OMIM ).

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

SOURCES: OMIM MENDELIAN

Medium match GALLOWAY-MOWAT SYNDROME 5; GAMOS5

Galloway-Mowat syndrome is a renal-neurologic disease characterized by early-onset nephrotic syndrome associated with microcephaly, gyral abnormalities, and delayed psychomotor development. Most patients have dysmorphic facial features, often including hypertelorism and ear abnormalities. Other features, such as arachnodactyly and visual or hearing impairment, are more variable. Most patients die in the first years of life (summary by Braun et al., 2017).For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (OMIM ).

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

SOURCES: OMIM MENDELIAN

Medium match GLYCOSYLPHOSPHATIDYLINOSITOL BIOSYNTHESIS DEFECT 15; GPIBD15

GPIBD15 is an autosomal recessive disorder characterized by delayed psychomotor development, variable intellectual disability, hypotonia, early-onset seizures in most patients, and cerebellar atrophy, resulting in cerebellar signs including gait ataxia and dysarthria. The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis (summary by Nguyen et al., 2017).For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (OMIM ).

GLYCOSYLPHOSPHATIDYLINOSITOL BIOSYNTHESIS DEFECT 15; GPIBD15 Is also known as developmental delay, epilepsy, cerebellar atrophy, and osteopenia

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

SOURCES: OMIM MENDELIAN

Medium match SCLEROSTEOSIS 2; SOST2

Sclerosteosis is a severe sclerosing bone dysplasia characterized by progressive skeletal overgrowth. Syndactyly is a variable manifestation. The disorder is rare and the majority of affected individuals have been reported in the Afrikaner population of South Africa (summary by Brunkow et al., 2001).For a discussion of genetic heterogeneity of sclerosteosis, see SOST1 (OMIM ).

• Hearing impairment
• Hypertelorism
• Macrocephaly
• Gait disturbance
• Frontal bossing

SOURCES: OMIM MENDELIAN

Medium match SPINOCEREBELLAR ATAXIA 42, EARLY-ONSET, SEVERE, WITH NEURODEVELOPMENTAL DEFICITS; SCA42ND

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

SOURCES: OMIM MENDELIAN

Medium match JOUBERT SYNDROME 26; JBTS26

Joubert syndrome-26 is an autosomal recessive ciliopathy characterized by global developmental delay associated with cerebellar hypoplasia and variable additional abnormalities, including hypotonia and possibly pituitary abnormalities (summary by Sanders et al., 2015).For a phenotypic description and a discussion of genetic heterogeneity of Joubert syndrome, see {213300}.

• Global developmental delay
• Short stature
• Generalized hypotonia
• Ataxia
• Hypertelorism

SOURCES: OMIM MENDELIAN

Medium match GALLOWAY-MOWAT SYNDROME 2, X-LINKED; GAMOS2

Galloway-Mowat syndrome is a renal-neurologic disease characterized by early-onset nephrotic syndrome associated with microcephaly, gyral abnormalities of the brain, and delayed psychomotor development. Most patients have dysmorphic facial features, often including hypertelorism, ear abnormalities, and micrognathia. Other features, such as arachnodactyly and visual impairment, are more variable. Most patients die in the first years of life (summary by Braun et al., 2017).For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (OMIM ).

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

SOURCES: OMIM MENDELIAN

Medium match PEROXISOME BIOGENESIS DISORDER 4B; PBD4B

Peroxisome biogenesis disorder-4B (PDB4B) includes the overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD), which represent milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders (PBDs). The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012).For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see {601539}.Individuals with mutations in the PEX6 gene have cells of complementation group 4 (CG4, equivalent to CG6 and CGC). For information on the history of PBD complementation groups, see {214100}.

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

SOURCES: OMIM MENDELIAN

Medium match AHDC1-RELATED INTELLECTUAL DISABILITY-OBSTRUCTIVE SLEEP APNEA-MILD DYSMORPHISM SYNDROME

AHDC1-related intellectual disability-obstructive sleep apnea-mild dysmorphism syndrome is a rare, syndromic intellectual disability characterized by hypotonia, developmetal delay, absent or severly delayed speech development, intellectual disability, obstructive sleep apnea, mild dysmorphic facial features and behavioral abnormalities. Epilepsy, ataxia and nystagmus have also been reported.

AHDC1-RELATED INTELLECTUAL DISABILITY-OBSTRUCTIVE SLEEP APNEA-MILD DYSMORPHISM SYNDROME Is also known as mrd25|xia-gibbs syndrome|mental retardation, autosomal dominant 25

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

SOURCES: OMIM ORPHANET MENDELIAN

Medium match MENTAL RETARDATION, X-LINKED, SYNDROMIC, BAIN TYPE; MRXSB

MRXSB is an X-linked dominant neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability with behavioral abnormalities, and dysmorphic facial features. Additional variable features include musculoskeletal abnormalities, seizures, acquired microcephaly, and feeding problems with poor overall growth. Only females are affected (summary by Bain et al., 2016).

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

SOURCES: OMIM MENDELIAN