Ataxia, and Astigmatism

Low match USHER SYNDROME TYPE 3

Usher syndrome type III is characterized by postlingual, progressive hearing loss, variable vestibular dysfunction, and onset of retinitis pigmentosa symptoms, including nyctalopia, constriction of the visual fields, and loss of central visual acuity, usually by the second decade of life (Karjalainen et al., 1985; Pakarinen et al., 1995).For a discussion of phenotypic heterogeneity of Usher syndrome, see USH1 (OMIM ). Genetic Heterogeneity of Usher syndrome Type IIIUsher syndrome type IIIB (OMIM ) is caused by mutation in the HARS gene (OMIM ) on chromosome 5q31.3.

USHER SYNDROME TYPE 3 Is also known as ush3|usher syndrome, type iii

• Hearing impairment
• Ataxia
• Neoplasm
• Sensorineural hearing impairment
• Cataract

SOURCES: ORPHANET OMIM MENDELIAN

Low match LEUKODYSTROPHY, HYPOMYELINATING, 11; HLD11

Hypomyelinating leukodystrophy-11 is an autosomal recessive neurologic disorder characterized by delayed psychomotor development and other neurologic features associated with hypomyelination on brain imaging. Some patients may have additional nonneurologic features, particularly dental abnormalities and possibly hypogonadotropic hypogonadism (summary by Thiffault et al., 2015).For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see {312080}.

• Intellectual disability
• Global developmental delay
• Ataxia
• Spasticity
• Myopia

SOURCES: OMIM MENDELIAN

Low match CONGENITAL FIBROSIS OF EXTRAOCULAR MUSCLES

Congenital fibrosis of the extraocular muscles (CFEOM) encompasses several different inherited strabismus syndromes characterized by congenital restrictive ophthalmoplegia affecting extraocular muscles innervated by the oculomotor and/or trochlear nerves. Classic CFEOM is characterized by bilateral blepharoptosis and ophthalmoplegia with the eyes fixed in an infraducted position about 20 to 30 degrees below the horizontal midline. Involvement of the horizontal extraocular muscles is variable. If all affected members of a family have the classic phenotype with bilateral involvement, the disorder is referred to as 'CFEOM1' (Engle et al., 1997; Heidary et al., 2008).CFEOM2 (OMIM ), an autosomal recessive disorder caused by mutation in the ARIX gene (OMIM ) on chromosome 11q13, is characterized by bilateral ptosis with eyes fixed in an exotropic position.The CFEOM3 phenotype shows more variable clinical features: affected individuals may have unilateral eye involvement, may be able raise their eyes above midline, or may not have blepharoptosis. CFEOM3 is diagnosed in a family if even 1 member does not have classic findings of the disorder. CFEOM3 is a genetically heterogeneous disorder; CFEOM3A with or without extraocular involvement (OMIM ) is caused by mutation in the TUBB3 gene (OMIM ) on chromosome 16q24; CFEOM3B is caused by mutation in the KIF21A gene (OMIM ) on chromosome 12q12; and CFEOM3C (OMIM ) maps to chromosome 13q.CFEOM4 (OMIM ), also known as Tukel syndrome, maps to chromosome 21q.CFEOM5 (OMIM ) is caused by mutation in the COL25A1 gene (OMIM ) on chromosome 4q25.See also NOMENCLATURE below.

CONGENITAL FIBROSIS OF EXTRAOCULAR MUSCLES Is also known as feom|feom1 locus|ophthalmoplegia, congenital|blepharoptosis with absent eye movements

• Intellectual disability
• Ataxia
• Strabismus
• Ptosis
• Optic atrophy

SOURCES: OMIM ORPHANET MENDELIAN

Low match AUTOSOMAL RECESSIVE SPASTIC PARAPLEGIA TYPE 75

Autosomal recessive spastic paraplegia type 75 is a rare, complex hereditary spastic paraplegia characterized by an early onset and slow progression of spastic paraplegia associated with cerebellar signs, nystagmus, peripheral neuropathy, extensor plantar responses and borderline to mild intellectual disability. Additional features of hypo- or areflexia, mild upper limb involvement and significant visual impairment (optic atrophy, vision loss, astigmatism) have been reported.

AUTOSOMAL RECESSIVE SPASTIC PARAPLEGIA TYPE 75 Is also known as spg75

• Intellectual disability
• Global developmental delay
• Generalized hypotonia
• Nystagmus
• Spasticity

SOURCES: OMIM ORPHANET MENDELIAN

Low match PONTOCEREBELLAR HYPOPLASIA TYPE 8

Pontocerebellar hypoplasia type 8 (PCH8) is a novel very rare form of pontocerebellar hypoplasia (see this term) characterized clinically by progressive microencephaly, feeding difficulties, severe developmental delay, although walking may be achieved, hypotonia often associated with increased muscle tone of lower extremities and deep tendon reflexes, joint deformities in the lower extremities, and occasionally complex seizures. PCH8 is caused by a loss-of-function mutation in the CHMP1A gene. MRI demonstrates a pontocerebellar hypoplasia with vermis and hemispheres equally affected and mild to severely reduced cerebral white matter volume with a fully formed very thin corpus callosum.

PONTOCEREBELLAR HYPOPLASIA TYPE 8 Is also known as pontocerebellar hypoplasia due to chmp1a mutation|pch8

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

SOURCES: OMIM ORPHANET MENDELIAN

Low match HERMANSKY-PUDLAK SYNDROME TYPE 7

HERMANSKY-PUDLAK SYNDROME TYPE 7 Is also known as hps7

• Ataxia
• Nystagmus
• Muscle weakness
• Respiratory distress
• Reduced visual acuity

SOURCES: ORPHANET OMIM MENDELIAN

Low match SHORT STATURE, RHIZOMELIC, WITH MICROCEPHALY, MICROGNATHIA, AND DEVELOPMENTAL DELAY; SRMMD

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Microcephaly

SOURCES: OMIM MENDELIAN

Low match HYPOTONIA, ATAXIA, AND DELAYED DEVELOPMENT SYNDROME; HADDS

Hypotonia, ataxia, and delayed development syndrome (HADDS) is a neurodevelopmental syndrome characterized by congenital hypotonia, delayed psychomotor development, variable intellectual disability with speech delay, variable dysmorphic facial features, and ataxia, often associated with cerebellar hypoplasia. Some patients may have urogenital abnormalities (summary by Sleven et al., 2017).

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

SOURCES: OMIM MENDELIAN

Low match XERODERMA PIGMENTOSUM, COMPLEMENTATION GROUP F; XPF

Xeroderma pigmentosum is an autosomal recessive disorder characterized by sun sensitivity and increased skin sensitivity to UV light, as well as an increased risk of skin cancer associated with a defect in nucleotide excision repair (NER). The XPF form of XP is usually relatively mild compared to other forms. Patients with XPF tend to have later onset of skin cancer. Some patients with XPF may develop neurologic impairment or growth defects, and are then classified as having Cockayne syndrome (summary by Kashiyama et al., 2013).For a general phenotypic description and a discussion of genetic heterogeneity of xeroderma pigmentosa, see XPA (OMIM ), and of Cockayne syndrome, see CSA (OMIM ).

XERODERMA PIGMENTOSUM, COMPLEMENTATION GROUP F; XPF Is also known as xp6|xp, group f|xeroderma pigmentosum vi

• Intellectual disability
• Short stature
• Hearing impairment
• Microcephaly
• Scoliosis

SOURCES: MESH OMIM MENDELIAN

Low match ANGELMAN SYNDROME; AS

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