raremaprare-disease reference indexOrphadata 2026-06-23 · HPO 2026-09-01
ORPHA:93932

FG syndrome type 1

Synonyms: Opitz-Kaveggia syndrome

Type
Disease
Group
Disorder
Inheritance
X-linked recessive
Age of onset
Antenatal, Neonatal
Status
active

A rare X-linked syndromic intellectual disability characterized by developmental delay and intellectual disability, early hypotonia, constipation, feeding problems, imperforate anus, characteristic behavior (affable, eager to please), and dysmorphic craniofacial features (such as relative macrocephaly, prominent forehead with frontal hair upsweep, hypertelorism, downslanting palpebral fissures, and open mouth). Additional manifestations are partial agenesis of the corpus callosum, sensorineural hearing loss, joint laxity, cardiac anomalies, and abnormalities of the fingers and toes, among others.

1

Names in Orphadata languages

12 of 12 languages
LangNameSynonyms
enFG syndrome type 1Opitz-Kaveggia syndrome
frSyndrome FG type 1Syndrome d'Opitz-Kaveggia
deFG-Syndrom Type 1Opitz-Kaveggia-Syndrom
esSíndrome FG tipo 1Síndrome de Opitz-Kaveggia
itSindrome FG, tipo 1Sindrome di Opitz-Kaveggia
nlFG-syndroom type 1Syndroom van Opitz-Kaveggia
ptSíndrome FG tipo 1
plZespół FG typu 1Zespół Opitza i Kaveggia
csFG syndrom typ 1Opitz-Kaveggiové syndrom
ukСиндром ФГ, тип 1Синдром Опітца-Кавеггіа
zhFG综合征1型Opitz-Kaveggia综合征
trFG sendromu tip 1Opitz-Kaveggia sendromu

Definition in:

2

Cross-references

qualifier = Orphanet mapping relation
SourceCodeQualifierICD relationValidation
OMIM305450Evalidated
ICD-10Q87.8NTBTattributedvalidated
ICD-11LD2F.1YNTBTindexvalidated
MONDO0010590Evalidated
MeSHC537923Evalidated
UMLSC5399762Evalidated
GARD2317Evalidated

E exact · NTBT this ORPHAcode is narrower than the target · BTNT broader than the target · ND not decided.

3

Classification

Preferential parent (Orphanet linearisation):

Parents in the classifications (4):

No children.

4

Genes

1 direct
GeneAssociationStatusHGNCEnsemblOMIMLocusNameSource of validation
MED12Disease-causing germline mutation(s) inAssessedHGNC:11957ENSG00000184634300188Xq13.1mediator complex subunit 1220301719[PMID]_17334363[PMID]
5

Prevalence and incidence

2 records
TypeClassValueAreaQualificationValidationSource
Prevalence at birthUnknown—WorldwideClass onlyValidated17574621[PMID]_ORPHANET
Point prevalenceUnknown—WorldwideClass onlyValidated17574621[PMID]_ORPHANET

Value is Orphadata's ValMoy: the mean estimate per 100 000 for prevalence and incidence, the number of cases or families for case reports.

6

HPO phenotypes

72 annotations · validated 2019-04-10
HPOTerm (as annotated by Orphanet)Diagnostic
Frequent (79-30%)
HP:0001317Abnormal cerebellum morphology
HP:0002250Abnormal large intestine morphology
HP:0000766Abnormal sternum morphology
HP:0007370Aplasia/Hypoplasia of the corpus callosum
HP:0001631Atrial septal defect
HP:0000475Broad neck
HP:0001837Broad toe
HP:0002136Broad-based gait
HP:0000028Cryptorchidism
HP:0000378Cupped ear
HP:0000750Delayed speech and language development
HP:0000678Dental crowding
HP:0000494Downslanted palpebral fissures
HP:0002307Drooling
HP:0002236Frontal upsweep of hair
HP:0011090Fused teeth
HP:0002761Generalized joint hypermobility
HP:0008935Generalized neonatal hypotonia
HP:0001263Global developmental delay
HP:0000348High forehead
HP:0000218High palate
HP:0000316Hypertelorism
HP:0000047Hypospadias
HP:0000023Inguinal hernia
HP:0002342Intellectual disability, moderate
HP:0005852Limited elbow extension and supination
HP:0000343Long philtrum
HP:0000256Macrocephaly
HP:0000272Malar flattening
HP:0004785Malrotation of colon
HP:0000347Micrognathia
HP:0008551Microtia
HP:0000609Optic nerve hypoplasia
HP:0001763Pes planus
HP:0001357Plagiocephaly
HP:0001622Premature birth
HP:0000448Prominent nose
HP:0000269Prominent occiput
HP:0002021Pyloric stenosis
HP:0004322Short stature
HP:0001533Slender build
HP:0012506Small pituitary gland
HP:0000402Stenosis of the external auditory canal
HP:0000486Strabismus
HP:0012471Thick vermilion border
HP:0002119Ventriculomegaly
HP:0000154Wide mouth
HP:0004492Widely patent fontanelles and sutures
Occasional (29-5%)
HP:0012433Abnormal social behavior
HP:0001172Abnormal thumb morphology
HP:0002023Anal atresia
HP:0007018Attention deficit hyperactivity disorder
HP:0000453Choanal atresia
HP:0040022Clinodactyly of the 2nd finger
HP:0001680Coarctation of aorta
HP:0000722Compulsive behaviors
HP:0002019Constipation
HP:0001363Craniosynostosis
HP:0009762Facial wrinkling
HP:0006101Finger syndactyly
HP:0002020Gastroesophageal reflux
HP:0000238Hydrocephalus
HP:0001634Mitral valve prolapse
HP:0000194Open mouth
HP:0005876Progressive flexion contractures
HP:0002092Pulmonary arterial hypertension
HP:0000960Sacral dimple
HP:0001250Seizure
HP:0000407Sensorineural hearing impairment
HP:0000331Short chin
HP:0000954Single transverse palmar crease
HP:0001537Umbilical hernia

Annotation source: 19938245[PMID]_4365204[PMID]

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Sources for this card