Mental Retardation, X-Linked, Syndromic, Christianson Type (MRXSCH)

Categories: Eye diseases, Fetal diseases, Genetic diseases, Mental diseases, Neuronal diseases, Rare diseases

Aliases & Classifications for Mental Retardation, X-Linked, Syndromic, Christianson Type

MalaCards integrated aliases for Mental Retardation, X-Linked, Syndromic, Christianson Type:

Name: Mental Retardation, X-Linked, Syndromic, Christianson Type 57 72 39 70
Mental Retardation Microcephaly Epilepsy and Ataxia Syndrome 72 6
Mental Retardation, X-Linked Syndromic, Christianson Type 57 13
X-Linked Angelman-Like Syndrome 58 72
Mrxsch 57 72
Mental Retardation, Microcephaly, Epilepsy, and Ataxia Syndrome 57
Angelman-Like Syndrome, X-Linked 57
Christianson Syndrome 58
Mrxs-Christianson 72


Orphanet epidemiological data:

christianson syndrome
Inheritance: X-linked dominant; Prevalence: <1/1000000 (Worldwide); Age of onset: Infancy,Neonatal; Age of death: young Adult;


57 (Updated 05-Apr-2021)
onset in infancy
progressive disorder
female carriers may be mildly affected
phenotypic similarities to angelman syndrome



mental retardation, x-linked, syndromic, christianson type:
Inheritance x-linked recessive inheritance


Orphanet: 58  
Rare neurological diseases
Rare eye diseases
Developmental anomalies during embryogenesis

Summaries for Mental Retardation, X-Linked, Syndromic, Christianson Type

OMIM® : 57 Christianson syndrome is an X-linked neurodevelopmental and progressive mental retardation syndrome characterized by microcephaly, impaired ocular movements, severe global developmental delay, developmental regression, hypotonia, abnormal movements, and early-onset seizures of variable types. Female carriers may be mildly affected (summary by Schroer et al., 2010 and Pescosolido et al., 2014). (300243) (Updated 05-Apr-2021)

MalaCards based summary : Mental Retardation, X-Linked, Syndromic, Christianson Type, also known as mental retardation microcephaly epilepsy and ataxia syndrome, is related to christianson syndrome and microcephaly, and has symptoms including ataxia, ophthalmoplegia and sleep disturbances. An important gene associated with Mental Retardation, X-Linked, Syndromic, Christianson Type is SLC9A6 (Solute Carrier Family 9 Member A6). Affiliated tissues include eye, cerebellum and skeletal muscle, and related phenotypes are dysphagia and microcephaly

UniProtKB/Swiss-Prot : 72 Mental retardation, X-linked, syndromic, Christianson type: A syndrome characterized by profound mental retardation, epilepsy, ataxia, and microcephaly. It shows phenotypic overlap with Angelman syndrome.

Related Diseases for Mental Retardation, X-Linked, Syndromic, Christianson Type

Graphical network of the top 20 diseases related to Mental Retardation, X-Linked, Syndromic, Christianson Type:

Diseases related to Mental Retardation, X-Linked, Syndromic, Christianson Type

Symptoms & Phenotypes for Mental Retardation, X-Linked, Syndromic, Christianson Type

Human phenotypes related to Mental Retardation, X-Linked, Syndromic, Christianson Type:

58 31 (show top 50) (show all 64)
# Description HPO Frequency Orphanet Frequency HPO Source Accession
1 dysphagia 58 31 very rare (1%) Frequent (79-30%) HP:0002015
2 microcephaly 58 31 very rare (1%) Frequent (79-30%) HP:0000252
3 strabismus 58 31 very rare (1%) Very frequent (99-80%) HP:0000486
4 absent speech 58 31 very rare (1%) Very frequent (99-80%) HP:0001344
5 cerebellar atrophy 58 31 very rare (1%) Very frequent (99-80%) HP:0001272
6 sleep disturbance 31 very rare (1%) HP:0002360
7 ataxia 31 very rare (1%) HP:0001251
8 open mouth 31 very rare (1%) HP:0000194
9 profound global developmental delay 31 very rare (1%) HP:0012736
10 drooling 31 very rare (1%) HP:0002307
11 hyperkinetic movements 31 very rare (1%) HP:0002487
12 interictal epileptiform activity 31 very rare (1%) HP:0011182
13 seizure 31 very rare (1%) HP:0001250
14 macrotia 58 31 Very frequent (99-80%) HP:0000400
15 mandibular prognathia 58 31 Occasional (29-5%) HP:0000303
16 thick eyebrow 58 31 Very frequent (99-80%) HP:0000574
17 ophthalmoplegia 58 31 Frequent (79-30%) HP:0000602
18 narrow face 58 31 Very frequent (99-80%) HP:0000275
19 long face 58 31 Very frequent (99-80%) HP:0000276
20 adducted thumb 58 31 Frequent (79-30%) HP:0001181
21 mutism 58 31 Frequent (79-30%) HP:0002300
22 truncal ataxia 58 31 Very frequent (99-80%) HP:0002078
23 neuronal loss in central nervous system 58 31 Very frequent (99-80%) HP:0002529
24 nystagmus 58 Frequent (79-30%)
25 developmental regression 58 Very frequent (99-80%)
26 bowel incontinence 31 HP:0002607
27 flexion contracture 31 HP:0001371
28 gastroesophageal reflux 58 Frequent (79-30%)
29 feeding difficulties in infancy 58 Frequent (79-30%)
30 stereotypy 58 Frequent (79-30%)
31 decreased muscle mass 58 Occasional (29-5%)
32 intellectual disability, severe 31 HP:0010864
33 skeletal muscle atrophy 31 HP:0003202
34 autism 58 Frequent (79-30%)
35 pectus excavatum 58 Frequent (79-30%)
36 cerebral cortical atrophy 58 Frequent (79-30%)
37 intellectual disability, progressive 31 HP:0006887
38 cachexia 58 Very frequent (99-80%)
39 aplasia/hypoplasia of the cerebellum 58 Very frequent (99-80%)
40 deeply set eye 58 Occasional (29-5%)
41 ventriculomegaly 58 Frequent (79-30%)
42 joint hyperflexibility 58 Occasional (29-5%)
43 abnormality of the thorax 58 Frequent (79-30%)
44 death in early adulthood 58 Occasional (29-5%)
45 dystonia 58 Frequent (79-30%)
46 narrow chest 31 HP:0000774
47 severe global developmental delay 58 Very frequent (99-80%)
48 arthrogryposis multiplex congenita 58 Occasional (29-5%)
49 decreased body weight 31 HP:0004325
50 abnormality of the nose 58 Occasional (29-5%)

Symptoms via clinical synopsis from OMIM®:

57 (Updated 05-Apr-2021)
Neurologic Central Nervous System:
sleep disturbance
developmental regression
cerebellar atrophy
truncal ataxia
Head And Neck Head:

Head And Neck Mouth:
open mouth

Genitourinary Bladder:
urinary incontinence

Muscle Soft Tissue:

Head And Neck Ears:
large ears

Head And Neck Face:
long, narrow face
square, prognathic jaw
pointed jaw

Skeletal Limbs:

Head And Neck Nose:
long, straight nose

Abdomen Gastrointestinal:
bowel incontinence
gastroesophageal reflux

Head And Neck Eyes:
bushy eyebrows
eye movement abnormalities
deep, sunken eyes

Chest External Features:
narrow chest

Neurologic Behavioral Psychiatric Manifestations:
happy demeanor
autistic features
easily provoked laughter

Growth Other:
developmental delay

Skeletal Hands:
adducted thumbs
long, thin fingers

Skin Nails Hair Hair:
bushy eyebrows

Growth Weight:
low weight (third percentile)

Skeletal Feet:
long, thin toes

Clinical features from OMIM®:

300243 (Updated 05-Apr-2021)

UMLS symptoms related to Mental Retardation, X-Linked, Syndromic, Christianson Type:

ataxia; ophthalmoplegia; sleep disturbances; ataxia, truncal

Drugs & Therapeutics for Mental Retardation, X-Linked, Syndromic, Christianson Type

Search Clinical Trials , NIH Clinical Center for Mental Retardation, X-Linked, Syndromic, Christianson Type

Genetic Tests for Mental Retardation, X-Linked, Syndromic, Christianson Type

Anatomical Context for Mental Retardation, X-Linked, Syndromic, Christianson Type

MalaCards organs/tissues related to Mental Retardation, X-Linked, Syndromic, Christianson Type:

Eye, Cerebellum, Skeletal Muscle

Publications for Mental Retardation, X-Linked, Syndromic, Christianson Type

Articles related to Mental Retardation, X-Linked, Syndromic, Christianson Type:

# Title Authors PMID Year
A new family with an SLC9A6 mutation expanding the phenotypic spectrum of Christianson syndrome. 57 6
27256868 2016
Genetic and phenotypic diversity of NHE6 mutations in Christianson syndrome. 6 57
25044251 2014
A mutation affecting the sodium/proton exchanger, SLC9A6, causes mental retardation with tau deposition. 6 57
20395263 2010
SLC9A6 mutations cause X-linked mental retardation, microcephaly, epilepsy, and ataxia, a phenotype mimicking Angelman syndrome. 57 6
18342287 2008
X linked severe mental retardation, craniofacial dysmorphology, epilepsy, ophthalmoplegia, and cerebellar atrophy in a large South African kindred is localised to Xq24-q27. 57 6
10528855 1999
Natural history of Christianson syndrome. 57
20949524 2010
Mutation in the SLC9A6 gene is not a frequent cause of sporadic Angelman-like syndrome. 57
19471312 2009
Dual degradation mechanisms ensure disposal of NHE6 mutant protein associated with neurological disease. 6
19619532 2009
A systematic, large-scale resequencing screen of X-chromosome coding exons in mental retardation. 57
19377476 2009
X-linked Angelman-like syndrome caused by Slc9a6 knockout in mice exhibits evidence of endosomal-lysosomal dysfunction. 61
21964919 2011

Variations for Mental Retardation, X-Linked, Syndromic, Christianson Type

ClinVar genetic disease variations for Mental Retardation, X-Linked, Syndromic, Christianson Type:

6 (show top 50) (show all 95)
# Gene Name Type Significance ClinVarId dbSNP ID Position
1 SLC9A6 NM_006359.3(SLC9A6):c.764_769del (p.Glu255_Ser256del) Deletion Pathogenic 11476 rs886037619 GRCh37: X:135084330-135084335
GRCh38: X:136002171-136002176
2 SLC9A6 NM_006359.3(SLC9A6):c.507+3_507+4delinsCC Indel Pathogenic 11478 rs730882187 GRCh37: X:135080347-135080348
GRCh38: X:135998188-135998189
3 SLC9A6 NM_006359.3(SLC9A6):c.512_513del (p.His171fs) Deletion Pathogenic 11479 rs730882188 GRCh37: X:135080645-135080646
GRCh38: X:135998486-135998487
4 SLC9A6 NM_006359.3(SLC9A6):c.916_924del (p.Gly306_Ala308del) Deletion Pathogenic 29949 rs398122849 GRCh37: X:135092713-135092721
GRCh38: X:136010554-136010562
5 SLC9A6 NM_006359.3(SLC9A6):c.1543G>T (p.Glu515Ter) SNV Pathogenic 92121 rs398123003 GRCh37: X:135112313-135112313
GRCh38: X:136030154-136030154
6 SLC9A6 NM_001042537.1(SLC9A6):c.183del (p.Lys61fs) Deletion Pathogenic 159931 rs587784398 GRCh37: X:135067844-135067844
GRCh38: X:135985685-135985685
7 SLC9A6 NM_001042537.1(SLC9A6):c.2078T>G (p.Leu693Ter) SNV Pathogenic 159932 rs587784399 GRCh37: X:135126855-135126855
GRCh38: X:136044696-136044696
8 SLC9A6 NM_001042537:c.916delC Deletion Pathogenic 246605 GRCh37:
9 SLC9A6 NM_006359.3(SLC9A6):c.786del (p.Ala263fs) Deletion Pathogenic 375585 rs1057519394 GRCh37: X:135084354-135084354
GRCh38: X:136002195-136002195
10 SLC9A6 NM_006359.3(SLC9A6):c.1367-1G>A SNV Pathogenic 625179 rs1603215383 GRCh37: X:135106488-135106488
GRCh38: X:136024329-136024329
11 SLC9A6 NM_001042537.1(SLC9A6):c.1148G>A (p.Gly383Asp) SNV Pathogenic 813744 rs782108464 GRCh37: X:135095508-135095508
GRCh38: X:136013349-136013349
12 SLC9A6 NM_001379110.1(SLC9A6):c.1246_1249del (p.Leu416fs) Microsatellite Pathogenic 949999 GRCh37: X:135104792-135104795
GRCh38: X:136022633-136022636
13 SLC9A6 NM_006359.3(SLC9A6):c.1569_1573del (p.Arg524fs) Deletion Pathogenic 807688 rs1603219805 GRCh37: X:135115588-135115592
GRCh38: X:136033429-136033433
14 SLC9A6 NM_006359.3(SLC9A6):c.1402C>T (p.Arg468Ter) SNV Pathogenic 11477 rs122461162 GRCh37: X:135106524-135106524
GRCh38: X:136024365-136024365
15 SLC9A6 NM_006359.3(SLC9A6):c.478_479AT[1] (p.Phe161fs) Microsatellite Pathogenic 627623 rs1603198063 GRCh37: X:135080315-135080316
GRCh38: X:135998156-135998157
16 SLC9A6 NM_006359.3(SLC9A6):c.751_753CTT[1] (p.Leu252del) Microsatellite Likely pathogenic 804087 rs1603201557 GRCh37: X:135084320-135084322
GRCh38: X:136002161-136002163
17 SLC9A6 NM_006359.3(SLC9A6):c.1376G>A (p.Gly459Asp) SNV Likely pathogenic 577815 rs1569525357 GRCh37: X:135106498-135106498
GRCh38: X:136024339-136024339
18 SLC9A6 NM_006359.3(SLC9A6):c.803+1G>A SNV Likely pathogenic 432837 rs1556617455 GRCh37: X:135084373-135084373
GRCh38: X:136002214-136002214
19 SLC9A6 NM_001042537.1(SLC9A6):c.1299_1300del (p.Phe434fs) Deletion Likely pathogenic 418996 rs1064793575 GRCh37: X:135098865-135098866
GRCh38: X:136016706-136016707
20 SLC9A6 NM_001042537.1(SLC9A6):c.526-9_526-5del Deletion Likely pathogenic 207248 rs796053290 GRCh37: X:135080254-135080258
GRCh38: X:135998095-135998099
21 SLC9A6 NM_001379110.1(SLC9A6):c.1555G>A (p.Gly519Ser) SNV Uncertain significance 943113 GRCh37: X:135112295-135112295
GRCh38: X:136030136-136030136
22 SLC9A6 NM_001379110.1(SLC9A6):c.1996C>T (p.Pro666Ser) SNV Uncertain significance 945766 GRCh37: X:135126839-135126839
GRCh38: X:136044680-136044680
23 SLC9A6 NM_001379110.1(SLC9A6):c.1582G>A (p.Gly528Ser) SNV Uncertain significance 951462 GRCh37: X:135115573-135115573
GRCh38: X:136033414-136033414
24 SLC9A6 NM_001379110.1(SLC9A6):c.992-3T>C SNV Uncertain significance 969959 GRCh37: X:135095505-135095505
GRCh38: X:136013346-136013346
25 SLC9A6 NM_001379110.1(SLC9A6):c.-57+50G>C SNV Uncertain significance 1030062 GRCh37: X:135067686-135067686
GRCh38: X:135985527-135985527
26 SLC9A6 NM_001379110.1(SLC9A6):c.1080+17A>G SNV Uncertain significance 1032437 GRCh37: X:135095613-135095613
GRCh38: X:136013454-136013454
27 SLC9A6 NM_001379110.1(SLC9A6):c.1420G>T (p.Gly474Cys) SNV Uncertain significance 1035423 GRCh37: X:135106602-135106602
GRCh38: X:136024443-136024443
28 overlap with 2 genes NC_000023.10:g.(?_135080257)_(135292184_?)dup Duplication Uncertain significance 1036230 GRCh37: X:135080257-135292184
29 SLC9A6 NM_001379110.1(SLC9A6):c.1876G>A (p.Ala626Thr) SNV Uncertain significance 1038955 GRCh37: X:135126719-135126719
GRCh38: X:136044560-136044560
30 SLC9A6 NM_006359.3(SLC9A6):c.512A>T (p.His171Leu) SNV Uncertain significance 207233 rs796053275 GRCh37: X:135080645-135080645
GRCh38: X:135998486-135998486
31 SLC9A6 NM_001379110.1(SLC9A6):c.-57+62C>T SNV Uncertain significance 1040525 GRCh37: X:135067698-135067698
GRCh38: X:135985539-135985539
32 SLC9A6 NM_006359.3(SLC9A6):c.1558C>A (p.Pro520Thr) SNV Uncertain significance 207253 rs782145804 GRCh37: X:135115579-135115579
GRCh38: X:136033420-136033420
33 SLC9A6 NM_006359.3(SLC9A6):c.712A>G (p.Ile238Val) SNV Uncertain significance 646158 rs782677140 GRCh37: X:135084281-135084281
GRCh38: X:136002122-136002122
34 SLC9A6 NM_006359.3(SLC9A6):c.453T>G (p.Phe151Leu) SNV Uncertain significance 647660 rs1603198044 GRCh37: X:135080290-135080290
GRCh38: X:135998131-135998131
35 SLC9A6 NM_006359.3(SLC9A6):c.227_244del (p.Ile76_Leu81del) Deletion Uncertain significance 653174 rs1603184929 GRCh37: X:135067881-135067898
GRCh38: X:135985722-135985739
36 SLC9A6 NM_006359.3(SLC9A6):c.543A>G (p.Ala181=) SNV Uncertain significance 656614 rs781961294 GRCh37: X:135080676-135080676
GRCh38: X:135998517-135998517
37 SLC9A6 NM_006359.3(SLC9A6):c.7C>T (p.Arg3Trp) SNV Uncertain significance 657261 rs1556614701 GRCh37: X:135067668-135067668
GRCh38: X:135985509-135985509
38 SLC9A6 NM_001379110.1(SLC9A6):c.13A>C (p.Ile5Leu) SNV Uncertain significance 964337 GRCh37: X:135067830-135067830
GRCh38: X:135985671-135985671
39 SLC9A6 NM_001379110.1(SLC9A6):c.506T>A (p.Ile169Asn) SNV Uncertain significance 988715 GRCh37: X:135080699-135080699
GRCh38: X:135998540-135998540
40 SLC9A6 NM_001379110.1(SLC9A6):c.821T>C (p.Ile274Thr) SNV Uncertain significance 988730 GRCh37: X:135092678-135092678
GRCh38: X:136010519-136010519
41 SLC9A6 NC_000023.11:g.(?_135985483)_(136024503_?)dup Duplication Uncertain significance 831697 GRCh37: X:135067642-135106662
42 SLC9A6 NM_006359.3(SLC9A6):c.1904T>G (p.Phe635Cys) SNV Uncertain significance 834464 GRCh37: X:135126777-135126777
GRCh38: X:136044618-136044618
43 SLC9A6 NM_006359.3(SLC9A6):c.8G>T (p.Arg3Leu) SNV Uncertain significance 572609 rs1016216648 GRCh37: X:135067669-135067669
GRCh38: X:135985510-135985510
44 SLC9A6 NM_006359.3(SLC9A6):c.619G>A (p.Val207Ile) SNV Uncertain significance 575064 rs1556616995 GRCh37: X:135081049-135081049
GRCh38: X:135998890-135998890
45 SLC9A6 NM_006359.3(SLC9A6):c.362A>G (p.His121Arg) SNV Uncertain significance 409978 rs1060502675 GRCh37: X:135076981-135076981
GRCh38: X:135994822-135994822
46 SLC9A6 NM_006359.3(SLC9A6):c.1488C>T (p.Gly496=) SNV Uncertain significance 469634 rs782370742 GRCh37: X:135106610-135106610
GRCh38: X:136024451-136024451
47 SLC9A6 NM_006359.3(SLC9A6):c.946G>A (p.Val316Met) SNV Uncertain significance 469638 rs1556618832 GRCh37: X:135095108-135095108
GRCh38: X:136012949-136012949
48 SLC9A6 NM_006359.3(SLC9A6):c.269T>C (p.Leu90Pro) SNV Uncertain significance 469635 rs1556614843 GRCh37: X:135067930-135067930
GRCh38: X:135985771-135985771
49 SLC9A6 NM_006359.3(SLC9A6):c.485A>G (p.Tyr162Cys) SNV Uncertain significance 469636 rs1556616834 GRCh37: X:135080322-135080322
GRCh38: X:135998163-135998163
50 SLC9A6 NM_001042537.1(SLC9A6):c.367C>T (p.Pro123Ser) SNV Uncertain significance 159934 rs587784400 GRCh37: X:135076986-135076986
GRCh38: X:135994827-135994827

UniProtKB/Swiss-Prot genetic disease variations for Mental Retardation, X-Linked, Syndromic, Christianson Type:

# Symbol AA change Variation ID SNP ID
1 SLC9A6 p.Gly186Arg VAR_083536

Expression for Mental Retardation, X-Linked, Syndromic, Christianson Type

Search GEO for disease gene expression data for Mental Retardation, X-Linked, Syndromic, Christianson Type.

Pathways for Mental Retardation, X-Linked, Syndromic, Christianson Type

GO Terms for Mental Retardation, X-Linked, Syndromic, Christianson Type

Sources for Mental Retardation, X-Linked, Syndromic, Christianson Type

9 Cosmic
10 dbSNP
11 DGIdb
17 EFO
18 ExPASy
19 FMA
28 GO
29 GTR
31 HPO
32 ICD10
33 ICD10 via Orphanet
37 LifeMap
41 MedGen
44 MeSH
45 MESH via Orphanet
46 MGI
49 NCI
50 NCIt
54 Novoseek
56 OMIM via Orphanet
57 OMIM® (Updated 05-Apr-2021)
61 PubMed
69 Tocris
71 UMLS via Orphanet
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