Ataxia, and Ichthyosis

Adult-onset neuronal ceroid lipofuscinosis, also known as Kufs disease, is a neurodegenerative disorder without retinal involvement. There are 2 overlapping phenotypes: type A, characterized by progressive myoclonic epilepsy, and type B, characterized by dementia and a variety of motor-system signs (summary by Arsov et al., 2011).In general, the neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005). The ultrastructural pattern of lipopigment in CLN4 comprises a mixed pattern of 'granular,' 'curvilinear,' and 'fingerprint' profiles. (Mole et al., 2005).For a general phenotypic description and a discussion of genetic heterogeneity of CLN, see CLN1 (OMIM ).

• Intellectual disability
• Seizures
• Ataxia
• Blindness
• Cerebellar atrophy

SOURCES: OMIM 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

The CDG (Congenital Disorders of Glycosylation) syndromes are a group of autosomal recessive disorders affecting glycoprotein synthesis. CDG syndrome type If is characterised by psychomotor delay, seizures, failure to thrive, and cutaneous and ocular anomalies.

MPDU1-CDG Is also known as congenital disorder of glycosylation type 1f|cdg syndrome type if|cdg-if|cdgif|cdg1f|carbohydrate deficient glycoprotein syndrome type if|congenital disorder of glycosylation type if|cdg if

• Seizures
• Global developmental delay
• Generalized hypotonia
• Microcephaly
• Ataxia

SOURCES: OMIM MESH ORPHANET MENDELIAN

CHANARIN-DORFMAN SYNDROME; CDS Is also known as neutral lipid storage disease with ichthyosis|dcs|nlsdi|triglyceride storage disease with impaired long-chain fatty acid oxidation|dorfman-chanarin syndrome|chanarin-dorfman disease|ichthyosiform erythroderma with leukocyte vacuolation|ichthyotic neutral

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

SOURCES: OMIM ORPHANET MENDELIAN

DORFMAN-CHANARIN DISEASE Is also known as neutral lipid storage disease with ichthyosis|nlsdi

SOURCES: ORPHANET MENDELIAN

While most patients of PBD complementation group 11 manifest rhizomelic chondrodysplasia punctata (RCDP1 ), a few have been reported with unusually mild phenotypes with longer survival, less neurologic involvement, normal or near-normal growth, and absence of rhizomelia (Braverman et al., 2002). In some cases this phenotype was indistinguishable from that of classic Refsum disease (OMIM ) and patients carried this diagnosis.Individuals with PBDs of complementation group 11 (CG11, equivalent to CGR) have mutations in the PEX7 gene. For information on the history of PBD complementation groups, see {214100}.

PEROXISOME BIOGENESIS DISORDER 9B; PBD9B Is also known as refsum disease, adult, 2|peroxisome biogenesis disorder, pex7-related, atypical

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

SOURCES: OMIM MENDELIAN

Kallmann syndrome (KS) is a developmental genetic disorder characterized by the association of congenital hypogonadotropic hypogonadism (CHH) due to gonadotropin-releasing hormone (GnRH) deficiency, and anosmia or hyposmia (with hypoplasia or aplasia of the olfactory bulbs).

KALLMANN SYNDROME Is also known as congenital hypogonadotropic hypogonadism with anosmia|olfacto-genital pathological sequence

• Seizures
• Ataxia
• Nystagmus
• Sensorineural hearing impairment
• Muscle weakness

SOURCES: ORPHANET MENDELIAN

NPHS14 is an autosomal recessive syndromic form of steroid-resistant nephrotic syndrome with multisystemic manifestations. Most affected individuals present in infancy or early childhood with progressive renal dysfunction associated with focal segmental glomerulosclerosis (FSGS) and resulting in end-stage renal disease within a few years. Other infants present with primary adrenal insufficiency. Some patients present in utero with fetal hydrops and fetal demise. Additional features of the disorder can include ichthyosis, acanthosis, adrenal insufficiency, immunodeficiency, and neurologic defects (summary by Prasad et al., 2017 and Lovric et al., 2017).For a discussion of genetic heterogeneity of nephrotic syndrome and FSGS, see NPHS1 (OMIM ).

FAMILIAL STEROID-RESISTANT NEPHROTIC SYNDROME WITH ADRENAL INSUFFICIENCY Is also known as primary adrenal insufficiency-steroid-resistant nephrotic syndrome due to sgpl1 deficiency

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

SOURCES: ORPHANET OMIM MENDELIAN

Trichothiodystrophy is a rare autosomal recessive disorder in which patients have brittle, sulfur-deficient hair that displays a diagnostic alternating light and dark banding pattern, called 'tiger tail banding,' under polarizing microscopy. TTD patients display a wide variety of clinical features, including cutaneous, neurologic, and growth abnormalities. Common additional clinical features are ichthyosis, intellectual/developmental disabilities, decreased fertility, abnormal characteristics at birth, ocular abnormalities, short stature, and infections. There are both photosensitive and nonphotosensitive forms of the disorder (summary by Faghri et al., 2008).Sabinas brittle hair syndrome (OMIM ) is another form of nonphotosensitive TTD.For a discussion of genetic heterogeneity of trichothiodystrophy, see {601675}.

TRICHOTHIODYSTROPHY 4, NONPHOTOSENSITIVE; TTD4 Is also known as trichothiodystrophy-neurocutaneous syndrome|pollitt syndrome|abhs|trichothiodystrophy, nonphotosensitive 1|bids syndrome|ttdn1|amish brittle hair brain syndrome|hair-brain syndrome

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

SOURCES: OMIM MENDELIAN

Refsum disease is an autosomal recessive inborn error of lipid metabolism classically characterized by a tetrad of clinical abnormalities: retinitis pigmentosa, peripheral neuropathy, cerebellar ataxia, and elevated protein levels in the cerebrospinal fluid (CSF) without an increase in the number of cells. However, not all patients show all these features. All patients have accumulation of an unusual branched-chain fatty acid, phytanic acid, in blood and tissues. Other variable features include cardiac dysfunction, nerve deafness, ichthyosis, and multiple epiphyseal dysplasia (review by Skjeldal et al., 1987).Increased levels of phytanic acid can also be found in peroxisomal biogenesis disorders; see Zellweger syndrome (see {214100}) (Skjeldal et al., 1987).Infantile Refsum disease (see PBD1B, {601539}) is a distinct disorder with a different phenotype and genetic basis.A phenotype clinically indistinguishable from that of classic Refsum disease (PBD9B ), but with a different biochemical profile, can be caused by mutation in the gene encoding peroxin-7 (PEX7 ) on chromosome 6q.

REFSUM DISEASE, CLASSIC Is also known as heredopathia atactica polyneuritiformis|hmsn iv|phytanic acid oxidase deficiency|hereditary motor and sensory neuropathy iv|hmsn4|refsum disease, adult, 1

• Seizures
• Global developmental delay
• Hearing impairment
• Ataxia
• Nystagmus

SOURCES: OMIM MENDELIAN