Ataxia, and Craniosynostosis

Low match JOUBERT SYNDROME 2; JBTS2

Joubert syndrome is a genetically heterogeneous autosomal recessive disorder characterized by a specific hindbrain malformation, which is referred to as the 'molar tooth sign' (MTS) on brain MRI, hypotonia, developmental delay, oculomotor apraxia, and breathing abnormalities. The complex brainstem malformation consists of cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (Maria et al., 1997). Additional features sometimes associated with Joubert syndrome include retinal anomalies, polydactyly, hepatic fibrosis, and renal disease. These related disorders are often referred to as 'cerebellooculorenal syndromes' (CORSs) (Chance et al., 1999; Satran et al., 1999).

JOUBERT SYNDROME 2; JBTS2 Is also known as cors2|cerebellooculorenal syndrome 2

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

SOURCES: MESH OMIM MENDELIAN

Low match ACROCEPHALOPOLYDACTYLOUS DYSPLASIA

Acrocephalopolydactylous dysplasia, or Elejalde syndrome, is a lethal multiple congenital disorder characterized by increased birth weight, globular body with thick skin, organomegaly, and fibrosis in multiple tissues (summary by Phadke et al., 2011).

ACROCEPHALOPOLYDACTYLOUS DYSPLASIA Is also known as elejalde syndrome

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

SOURCES: OMIM MENDELIAN

Low match SHORT-RIB THORACIC DYSPLASIA 9 WITH OR WITHOUT POLYDACTYLY; SRTD9

Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013).There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, {218330}).For a discussion of genetic heterogeneity of short-rib thoracic dysplasia, see SRTD1 (OMIM ).

SHORT-RIB THORACIC DYSPLASIA 9 WITH OR WITHOUT POLYDACTYLY; SRTD9 Is also known as mzsds|mainzer-saldino syndrome|renal dysplasia, retinal pigmentary dystrophy, cerebellar ataxia, and skeletal dysplasia|conorenal syndrome

• Seizures
• Global developmental delay
• Short stature
• Microcephaly
• Ataxia

SOURCES: OMIM MENDELIAN

Low match ADENYLOSUCCINATE LYASE DEFICIENCY

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

Low match MACROCEPHALY, DYSMORPHIC FACIES, AND PSYCHOMOTOR RETARDATION; MDFPMR

Macrocephaly, dysmorphic facies, and psychomotor retardation (MDFPMR) is an autosomal recessive neurodevelopmental disorder characterized by large head and somatic overgrowth apparent at birth followed by global developmental delay. Affected individuals have characteristic dysmorphic facial features and persistently large head, but increased birth weight normalizes with age. Additional neurologic features, including seizures, hypotonia, and gait ataxia, may also occur. Patients show severe intellectual impairment (summary by Ortega-Recalde et al., 2015).

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

SOURCES: OMIM MENDELIAN

Low match PERMANENT NEONATAL DIABETES MELLITUS

Permanent neonatal diabetes mellitus (PNDM) is a monogenic form of neonatal diabetes (NDM, see this term) characterized by persistent hyperglycemia within the first 12 months of life in general, requiring continuous insulin treatment.

PERMANENT NEONATAL DIABETES MELLITUS Is also known as monogenic diabetes of infancy|pndm

• Intellectual disability
• Global developmental delay
• Hearing impairment
• Ataxia
• Failure to thrive

SOURCES: ORPHANET MENDELIAN

Low match JOUBERT SYNDROME 21; JBTS21

Joubert syndrome is an autosomal recessive congenital condition characterized by a unique brainstem and cerebellar malformation comprising cerebellar vermis hypoplasia and/or dysplasia, elongated superior cerebellar peduncles, and deepened interpeduncular fossa, which together are recognized as the 'molar tooth sign' on brain MRI. The most common clinical features include delayed psychomotor development, hypotonia, abnormal respiratory patterns in the neonatal period, oculomotor apraxia, and cerebellar ataxia. Additional features may include retinal degeneration, cystic kidney, liver fibrosis, and polydactyly. It is caused by ciliary defects and is part of a spectrum of disorders known as 'ciliopathies' (summary by Akizu et al., 2014).For a phenotypic description and a discussion of genetic heterogeneity of Joubert syndrome, see {213300}.

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

SOURCES: OMIM MENDELIAN

Low match HYPOTONIA, ATAXIA, DEVELOPMENTAL DELAY, AND TOOTH ENAMEL DEFECT SYNDROME; HADDTS

• Intellectual disability
• Generalized hypotonia
• Feeding difficulties
• Delayed speech and language development
• Motor delay

SOURCES: OMIM MENDELIAN

Low match AUTOSOMAL RECESSIVE CEREBELLAR ATAXIA-EPILEPSY-INTELLECTUAL DISABILITY SYNDROME DUE TO TUD DEFICIENCY

Autosomal recessive cerebellar ataxia-epilepsy-intellectual disability syndrome due to TUD deficiency is a rare, hereditary ataxia characterized by an early onset symptomatic generalized epilepsy, progressive cerebellar ataxia resulting in significant difficulties to walk or wheelchair dependency, and intellectual disability.

AUTOSOMAL RECESSIVE CEREBELLAR ATAXIA-EPILEPSY-INTELLECTUAL DISABILITY SYNDROME DUE TO TUD DEFICIENCY Is also known as scar23|spinocerebellar ataxia autosomal recessive type 23

• Intellectual disability
• Seizures
• Generalized hypotonia
• Ataxia
• Abnormal facial shape

SOURCES: ORPHANET OMIM MENDELIAN

Low 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