Ataxia, and Hypoplasia of penis

Lissencephaly ('smooth brain') results from migrational arrest of cortical neurons short of their normal destination, and can result in profound mental retardation and seizures. In X-linked lissencephaly-1, affected males generally have more a severe phenotype compared to females. DCX mutations cause classic lissencephaly with mental retardation in hemizygous males and a milder phenotype known as subcortical band heterotopia in females, sometimes in the same family. The subcortical lamina heterotopia found in heterozygous females is also referred to as 'double cortex' (DC) syndrome (des Portes et al., 1997).There are several X-linked loci that affect neuronal migration, including the Aicardi locus (OMIM ).

LISSENCEPHALY, X-LINKED, 1; LISX1 Is also known as xlis|lissencephaly and agenesis of corpus callosum

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

SOURCES: OMIM MENDELIAN

West syndrome (or infantile spasms) is characterised by the association of clusters of axial spasms, psychomotor retardation and an hypsarrhythmic interictal EEG pattern. It is the most frequent type of epileptic encephalopathy. It may occur in otherwise healthy infants and in those with abnormal cognitive development.

WEST SYNDROME Is also known as intellectual disability-hypsarrhythmia syndrome|infantile spasm syndrome, x-linked 1|xmesid|west syndrome, x-linked|ohtahara syndrome, x-linked|infantile spasms|infantile epileptic-dyskinetic encephalopathy|issx1

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

SOURCES: OMIM ORPHANET MENDELIAN

Congenital idiopathic hypogonadotropic hypogonadism (IHH) is a disorder characterized by absent or incomplete sexual maturation by the age of 18 years, in conjunction with low levels of circulating gonadotropins and testosterone and no other abnormalities of the hypothalamic-pituitary axis. Idiopathic hypogonadotropic hypogonadism can be caused by an isolated defect in gonadotropin-releasing hormone (GNRH ) release, action, or both. Other associated nonreproductive phenotypes, such as anosmia, cleft palate, and sensorineural hearing loss, occur with variable frequency. In the presence of anosmia, idiopathic hypogonadotropic hypogonadism has been called 'Kallmann syndrome (KS),' whereas in the presence of a normal sense of smell, it has been termed 'normosmic idiopathic hypogonadotropic hypogonadism (nIHH)' (summary by Raivio et al., 2007). Because families have been found to segregate both KS and nIHH, the disorder is here referred to as 'hypogonadotropic hypogonadism with or without anosmia.'For information on the autosomal forms of hypogonadotropic hypogonadism with or without anosmia, see {147950}.

HYPOGONADOTROPIC HYPOGONADISM 1 WITH OR WITHOUT ANOSMIA; HH1 Is also known as anosmic hypogonadism|hha|kallmann syndrome 1|dysplasia olfactogenitalis of de morsier|hypogonadotropic hypogonadism and anosmia|kms|kal1

• Hearing impairment
• Ataxia
• Sensorineural hearing impairment
• Cleft palate
• Cryptorchidism

SOURCES: ORPHANET OMIM MENDELIAN

Cerebellar ataxia, mental retardation, and dysequilibrium syndrome (CAMRQ) is a genetically heterogeneous disorder characterized by congenital cerebellar ataxia and mental retardation (summary by Gulsuner et al., 2011).For a discussion of genetic heterogeneity of CAMRQ, see CAMRQ1 (OMIM ).

CEREBELLAR ATAXIA, MENTAL RETARDATION, AND DYSEQUILIBRIUM SYNDROME 2; CAMRQ2 Is also known as cerebellar ataxia and mental retardation with or without quadrupedal locomotion 2

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

SOURCES: MESH OMIM MENDELIAN

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

X-linked intellectual deficit-cerebellar hypoplasia, also known as OPHN1 syndrome, is a rare syndromic form of cerebellar dysgenesis characterized by moderate to severe intellectual deficit and cerebellar abnormalities.

X-LINKED INTELLECTUAL DISABILITY-CEREBELLAR HYPOPLASIA SYNDROME Is also known as oligophrenin-1 syndrome|ophn1 syndrome|mental retardation, x-linked 60, formerly|mrx60, formerly

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

SOURCES: OMIM ORPHANET MESH MENDELIAN

Laurence-Moon syndrome (LMS) is a very rare genetic multisystemic disorder characterized by pituitary dysfunction, ataxia, peripheral neuropathy, spastic paraplegia, and chorioretinal dystrophy.

• Intellectual disability
• Short stature
• Ataxia
• Nystagmus
• Strabismus

SOURCES: ORPHANET MENDELIAN

Acrocallosal syndrome (ACS) is a polymalformative syndrome characterized by agenesis of corpus callosum (CC), distal anomalies of limbs, minor craniofacial anomalies and intellectual deficit.

ACROCALLOSAL SYNDROME Is also known as acs

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

SOURCES: ORPHANET OMIM MENDELIAN

Laurence-Moon syndrome has a clinical presentation similar to that of Oliver-McFarlane syndrome (OMIM ), including chorioretinopathy and pituitary dysfunction, but with childhood onset of ataxia, peripheral neuropathy, and spastic paraplegia and without trichomegaly. Historically, Laurence-Moon syndrome has been associated with Bardet-Biedl syndrome (see BBS, {209900}) (summary by Hufnagel et al., 2015).Oliver-McFarlane syndrome is an allelic disorder.

• Intellectual disability
• Short stature
• Ataxia
• Growth delay
• Nystagmus

SOURCES: OMIM MENDELIAN

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

SOURCES: OMIM MENDELIAN