Ataxia, and Macroglossia

Lhermitte-Duclos disease (LDD) is a very rare disorder characterized by abnormal development and enlargement of the cerebellum, and an increased intracranial pressure.

LHERMITTE-DUCLOS DISEASE Is also known as dysplastic gangliocytoma of the cerebellum|ldd

• Seizures
• Ataxia
• Macrocephaly
• Hydrocephalus
• Headache

SOURCES: ORPHANET MENDELIAN

Intellectual disability-coarse face-macrocephaly-cerebellar hypotrophy syndrome is a rare, genetic, central nervous system malformation syndrome characterized by early-onset, progressive, severe cerebellar ataxia associated with progressive, moderate to severe intellecutal disability, global developmental delay, progressively coarsening facial features, relative macrocephaly and absence of seizures. Sensorineural hearing loss may be associated. Neuroimaging reveals cerebellar atrophy/hypoplasia.

INTELLECTUAL DISABILITY-COARSE FACE-MACROCEPHALY-CEREBELLAR HYPOTROPHY SYNDROME Is also known as intellectual disability-coarse face-macrocephaly-cerebellar hypoplasia syndrome|scar20|autosomal recessive spinocerebellar ataxia type 20

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

SOURCES: ORPHANET OMIM MENDELIAN

Sandhoff disease is a progressive neurodegenerative disorder characterized by an accumulation of GM2 gangliosides, particularly in neurons, and is clinically indistinguishable from Tay-Sachs disease (OMIM ).

SANDHOFF DISEASE, INFANTILE FORM Is also known as infantile gm2 gangliosidosis 0 variant|hexosaminidases a and b deficiency|hexosaminidases a and b deficiency, infantile form|gm2-gangliosidosis, type ii

• Intellectual disability
• Seizures
• Hearing impairment
• Ataxia
• Muscle weakness

SOURCES: OMIM ORPHANET MENDELIAN

Joubert syndrome is a clinically and genetically heterogeneous group of disorders characterized by hypoplasia of the cerebellar vermis with the characteristic neuroradiologic 'molar tooth sign,' and accompanying neurologic symptoms, including dysregulation of breathing pattern and developmental delay. Other variable features include retinal dystrophy and renal anomalies (Saraiva and Baraitser, 1992; Valente et al., 2005). Genetic Heterogeneity of Joubert SyndromeSee also JBTS2 (OMIM ), caused by mutation in the TMEM216 gene (OMIM ) on chromosome 11q13; JBTS3 (OMIM ), caused by mutation in the AHI1 gene (OMIM ) on chromosome 6q23; JBTS4 (OMIM ), caused by mutation in the NPHP1 gene (OMIM ) on chromosome 2q13; JBTS5 (OMIM ), caused by mutation in the CEP290 gene, also called NPHP6 (OMIM ), on chromosome 12q21.32; JBTS6 (OMIM ), caused by mutation in the TMEM67 gene (OMIM ) on chromosome 8q21; JBTS7 (OMIM ), caused by mutation in the RPGRIP1L gene (OMIM ) on chromosome 16q12.2; JBTS8 (OMIM ), caused by mutation in the ARL13B (OMIM ) on chromosome 3q11.2; JBTS9 (OMIM ), caused by mutation in the CC2D2A gene (OMIM ) on chromosome 4p15.3; JBTS10 (OMIM ), caused by mutation in the CXORF5 gene (OMIM ) on chromosome Xp22.3; JBTS11 (see {613820}), caused by mutation in the TTC21B gene (OMIM ) on chromosome 2q24; JBTS12 (see {200990}), caused by mutation in the KIF7 gene (OMIM ) on chromosome 15q26; JBTS13 (OMIM ), caused by mutation in the TCTN1 gene (OMIM ) on chromosome 12q24; JBTS14 (OMIM ), caused by mutation in the TMEM237 gene (OMIM ) on chromosome 2q33; JBTS15 (OMIM ), caused by mutation in the CEP41 gene (OMIM ) on chromosome 7q32; JBTS16 (OMIM ), caused by mutation in the TMEM138 gene (OMIM ) on chromosome 11q; JBTS17 (OMIM ), caused by mutation in the C5ORF42 gene (OMIM ) on chromosome 5p13; JBTS18 (OMIM ), caused by mutation in the TCTN3 gene (OMIM ) on chromosome 10q24; JBTS19 (see {614844}), caused by mutation in the ZNF423 gene (OMIM ) on chromosome 16q12; JBTS20 (OMIM ), caused by mutation in the TMEM231 gene (OMIM ) on chromosome 16q23; JBTS21 (OMIM ), caused by mutation in the CSPP1 gene (OMIM ) on chromosome 8q13; JBTS22 (OMIM ), caused by mutation in the PDE6D gene (OMIM ) on chromosome 2q37; JBTS23 (OMIM ), caused by mutation in the KIAA0586 gene (OMIM ) on chromosome 14q23; JBTS24 (OMIM ), caused by mutation in the TCTN2 gene (OMIM ) on chromosome 12q24; JBTS25 (OMIM ), caused by mutation in the CEP104 gene (OMIM ) on chromosome 1p36; JBTS26 (OMIM ), caused by mutation in the KIAA0556 gene (OMIM ) on chromosome 16p12; JBTS27 (OMIM ), caused by mutation in the B9D1 gene (OMIM ) on chromosome 17p11; JBTS28 (OMIM ), caused by mutation in the MKS1 gene (OMIM ) on chromosome 17q23; JBTS29 (see {617562}), caused by mutation in the TMEM107 gene (OMIM ) on chromosome 17p13; JBTS30 (OMIM ), caused by mutation in the ARMC9 gene (OMIM ) on chromosome 2q37; JBTS31 (OMIM ), caused by mutation in the CEP120 gene (OMIM ) on chromosome 5q23; JBTS32 (OMIM ), caused by mutation in the SUFU gene (OMIM ) on chromosome 10q24; and JBTS33 (OMIM ), caused by mutation in the PIBF1 gene (OMIM ) on chromosome 13q21.

JOUBERT SYNDROME 1; JBTS1 Is also known as cerebelloparenchymal disorder iv|jbts|cpd4|joubert syndrome|cerebellooculorenal syndrome 1|cors1|joubert-boltshauser syndrome

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

SOURCES: OMIM MENDELIAN

Angelman syndrome is a neurodevelopmental disorder characterized by mental retardation, movement or balance disorder, typical abnormal behaviors, and severe limitations in speech and language. Most cases are caused by absence of a maternal contribution to the imprinted region on chromosome 15q11-q13. Prader-Willi syndrome (PWS ) is a clinically distinct disorder resulting from paternal deletion of the same 15q11-q13 region. In addition, the chromosome 15q11-q13 duplication syndrome (OMIM ) shows overlapping clinical features.Clayton-Smith and Pembrey (1992) provided a review of Angelman syndrome. Cassidy and Schwartz (1998) reviewed the molecular and clinical aspects of both Prader-Willi syndrome and Angelman syndrome. Horsthemke and Wagstaff (2008) provided a detailed review of the mechanisms of imprinting of the Prader-Willi/Angelman syndrome region.Van Buggenhout and Fryns (2009) provided a review of Angelman syndrome and discussed genetic counseling of the disorder, which can show a recurrence risk of up to 50%, depending on the underlying genetic mechanism.

ANGELMAN SYNDROME; AS Is also known as happy puppet syndrome, formerly

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

SOURCES: ORPHANET OMIM MENDELIAN

GPIBD18 is a severe autosomal recessive developmental disorder characterized by severely impaired global development, hypotonia, weakness, ataxia, coarse facial features, and intractable seizures. More variable features may include abnormalities of the hands and feet, inguinal hernia, and feeding difficulties. The disorder is part of a group of similar neurologic disorders resulting from biochemical defects in the glycosylphosphatidylinositol (GPI) biosynthetic pathway (summary by Nguyen et al., 2018).For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (OMIM ).

• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment
• Ataxia

SOURCES: OMIM MENDELIAN

X-linked intellectual disability, Cabezas type is characterised by intellectual deficit, muscle wasting, short stature, a prominent lower lip, small testes, kyphosis and joint hyperextensibility. An abnormal gait, tremor, decreased fine motor coordination and impaired speech are also present. The syndrome has been described in six boys from three generations of the same family. Transmission is X-linked and the causative gene has been localised to the q24-q25 region of the X chromosome.

X-LINKED INTELLECTUAL DISABILITY, CABEZAS TYPE Is also known as cabezas syndrome|mrss|mrxs15|mental retardation, x-linked, with short stature|mental retardation, x-linked, with short stature, hypogonadism, and abnormal gait|mental retardation, x-linked, syndromic 15

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

SOURCES: OMIM ORPHANET MENDELIAN

Fucosidosis is an extremely rare lysosomal storage disorder characterized by a highly variable phenotype with common manifestations including neurologic deterioration, coarse facial features, growth retardation, and recurrent sinopulmonary infections, as well as seizures, visceromegaly, angiokeratoma and dysostosis.

FUCOSIDOSIS Is also known as alpha-l-fucosidase deficiency

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

SOURCES: ORPHANET MENDELIAN

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