Ataxia, and Abnormality of skin pigmentation

Nijmegen breakage syndrome-like disorder is a rare, genetic multiple congenital anomalies/dysmorphic syndrome characterized by growth retardation, short stature, developmental delay, intellectual disability, craniofacial dysmorphism (i.e. severe microcephaly, sloping forehead, prominent eyes, broad nasal ridge, hypoplastic nasal septum, epicanthal folds), spontaneous chromosomal instability, cellular hypersensitivity to ionizing radiation and radioresistant DNA synthesis, without severe infections, immunodeficiency or cancer predisposition. Additional reported features include mild spasticity, slight and nonprogressive ataxia, hyperopia, multiple pigmented nevi, widely spaced nipples, and clinodactyly.

NIJMEGEN BREAKAGE SYNDROME-LIKE DISORDER Is also known as microcephaly and chromosomal instability without immunodeficiency|nbsld|microcephaly and spontaneous chromosome instability without immunodeficiency|nbs-like disorder|rad50 deficiency

• Intellectual disability
• Short stature
• Microcephaly
• Ataxia
• Spasticity

SOURCES: MESH ORPHANET OMIM MENDELIAN

Abetalipoproteinemia and familial hypobetalipoproteinemia (FBHL ) are rare diseases characterized by hypocholesterolemia and malabsorption of lipid-soluble vitamins leading to retinal degeneration, neuropathy, and coagulopathy. Hepatic steatosis is also common. The root cause of both disorders is improper packaging and secretion of apolipoprotein B-containing particles. Obligate heterozygous parents of ABL patients usually have normal lipids consistent with autosomal recessive inheritance, whereas obligate heterozygous parents of FBHL patients typically have half normal levels of apoB-containing lipoproteins consistent with autosomal codominant inheritance (summary by Lee and Hegele, 2014).

ABETALIPOPROTEINEMIA; ABL Is also known as microsomal triglyceride transfer protein deficiency|acanthocytosis|bassen-kornzweig syndrome|mtp deficiency

• Ataxia
• Peripheral neuropathy
• Rod-cone dystrophy
• Abnormality of the liver
• Retinopathy

SOURCES: OMIM MENDELIAN

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

SOURCES: OMIM MENDELIAN

X-linked sideroblastic anemia is a constitutional microcytic, hypochromic anemia of varying severity that is clinically characterized by manifestations of anemia and iron overload and that may respond to treatment with pyridoxine and folic acid.

X-LINKED SIDEROBLASTIC ANEMIA Is also known as anemia, hereditary sideroblastic|xlsa|anemia, hypochromic|anemia, sideroblastic, x-linked|anh1|hereditary iron-loading anemia

• Ataxia
• Muscle weakness
• Anemia
• Hepatomegaly
• Fatigue

SOURCES: ORPHANET OMIM MENDELIAN

Elejalde syndrome (ES) is characterized by silvery to leaden hair, bronze skin colour in sun-exposed areas and severe neurological impairment.

NEUROECTODERMAL MELANOLYSOSOMAL DISEASE Is also known as elejalde disease

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

SOURCES: ORPHANET MENDELIAN

Waardenburg syndrome type 4 (WS4), also known as Waardenburg-Shah syndrome, is an auditory-pigmentary syndrome characterized by pigmentary abnormalities of the hair, skin, and eyes, congenital sensorineural hearing loss, and Hirschsprung disease (reviews by Read and Newton, 1997 and Pingault et al., 2010). WS type 4A is caused by mutation in the EDNRB gene (OMIM ). Clinical Variability of Waardenburg Syndrome Types 1-4Waardenburg syndrome has been classified into 4 main phenotypes. Type I Waardenburg syndrome (WS1 ) is characterized by pigmentary abnormalities of the hair, including a white forelock and premature graying; pigmentary changes of the iris, such as heterochromia iridis and brilliant blue eyes; congenital sensorineural hearing loss; and 'dystopia canthorum.' WS type II (WS2) is distinguished from type I by the absence of dystopia canthorum. WS type III (WS3 ) has dystopia canthorum and is distinguished by the presence of upper limb abnormalities. WS type 4 has the additional feature of Hirschsprung disease (reviews by Read and Newton, 1997 and Pingault et al., 2010). Genetic Heterogeneity of Waardenburg Syndrome Type 4Waardenburg syndrome type 4 is genetically heterogeneous. WS4B (OMIM ) is caused by mutation in the EDN3 gene (OMIM ) on chromosome 20q13, and WS4C (OMIM ) is caused by mutation in the SOX10 gene (OMIM ) on chromosome 22q13.

WAARDENBURG SYNDROME, TYPE 4A; WS4A Is also known as waardenburg-shah syndrome|waardenburg syndrome, type iva|ws4|waardenburg syndrome with hirschsprung disease, type 4a|shah-waardenburg syndrome

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

SOURCES: OMIM MENDELIAN

Autosomal recessive dyskeratosis congenita-6 is a bone marrow failure disorder associated with abnormal skin pigmentation, nail dystrophy, oral leukoplakia, microcephaly, and developmental delay (summary by Tummala et al., 2015).For a discussion of genetic heterogeneity of dyskeratosis congenita, see DKCA1 (OMIM ).

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

SOURCES: OMIM MENDELIAN

Piebaldism is a rare congenital pigmentation skin disorder characterized by the presence of hypopigmented and depigmented skin areas (leukoderma) on various parts of the body, preferentially on the forehead, chest, abdomen, upper arms, and lower extremities, that are associated with a white forelock (poliosis), and in some cases with hypopigmented and depigmented eyebrows and eyelashes.

PIEBALDISM Is also known as piebaldism

• Intellectual disability
• Hearing impairment
• Microcephaly
• Ataxia
• Neoplasm

SOURCES: OMIM MESH ORPHANET MENDELIAN

Griscelli syndrome type 1 (GS1) represents hypomelanosis with a primary neurologic deficit and without immunologic impairment or manifestations of hemophagocytic syndrome (Menasche et al., 2002). Griscelli syndrome with immune impairment, or Griscelli syndrome type 2 (OMIM ), is caused by mutation in the RAB27A gene (OMIM ). Griscelli syndrome type 3 (OMIM ), characterized by hypomelanosis with no immunologic or neurologic manifestations, can be caused by mutation in the melanophilin (MLPH ) or MYO5A genes.Griscelli syndrome is a rare autosomal recessive disorder that results in pigmentary dilution of the skin and hair, the presence of large clumps of pigment in hair shafts, and an accumulation of melanosomes in melanocytes. While most patients also develop hemophagocytic syndrome, leading to death in the absence of bone marrow transplantation (Menasche et al., 2000), some show severe neurologic impairment early in life without apparent immune abnormalities. Bahadoran et al. (2003) characterized GS1 as comprising hypomelanosis and severe central nervous system dysfunction, corresponding to the 'dilute' phenotype in the mouse, and GS2 as comprising hypomelanosis and lymphohistiocytotic hemophagocytosis, corresponding to the 'ashen' phenotype in mouse.Anikster et al. (2002), Menasche et al. (2002), Huizing et al. (2002), and {3,2:Bahadoran et al. (2003, 2003)} suggested that Elejalde syndrome (OMIM ) in some patients and GS1 represent the same entity.

GRISCELLI SYNDROME TYPE 1 Is also known as partial albinism and primary neurologic disease without hemophagocytic syndrome|griscelli syndrome, cutaneous and neurologic type|griscelli-pruniÉras syndrome type 1|hypopigmentation-neurologic impairment syndrome|griscelli syndrome with neurologic impair

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

SOURCES: MESH OMIM ORPHANET MENDELIAN

Revesz syndrome is a rare severe phenotypic variant of dyskeratosis congenita (DC; see this term) with an onset in early childhood, characterized by features of DC (e.g. skin hyper/hypopigmentation, nail dystrophy, oral leukoplakia, high risk of bone marrow failure (BMF) and cancer, developmental delay sparse and fine hair) in conjunction with bilateral exudative retinopathy, and intracranial calcifications.

REVESZ SYNDROME Is also known as exudative retinopathy with bone marrow failure|dkca5|dyskeratosis congenita, autosomal dominant 5|dyskeratosis congenita with bilateral exudative retinopathy|retinopathy-anemia-central nervous system anomalies syndrome|revesz-debuse syndrome

• Global developmental delay
• Ataxia
• Growth delay
• Nystagmus
• Anemia

SOURCES: OMIM ORPHANET MESH MENDELIAN