FB2026_03 , released September 17, 2026
Human Disease Model Report: Guillouet-Gordon syndrome
Open Close
General Information
Name
Guillouet-Gordon syndrome
FlyBase ID
FBhh0001651
Disease Ontology Term
Parent Disease
OMIM
GUILLOUET-GORDON SYNDROME; GGNS
Overview

This report describes Guillouet-Gordon syndrome, an autosomal recessive disorder with multiple congenital anomalies and impaired intellectual development. The human gene implicated is MED16, which encodes Mediator complex subunit 16, a transcription coactivator that participates in RNA polymerase II-dependent transcription. There is one high-scoring fly ortholog, Dmel\MED16, for which multiple genetic reagents, including classical alleles, RNAi-targeting constructs, alleles caused by insertional mutagenesis have been generated, and alleles representing disease-implicated variants have been generated.

The human gene MED16 has not been introduced into flies.

Hemizygous null alleles of Dmel\MED16 exhibit a mild decrease in eclosion rate at 29[o]C but not 22[o]C. This phenotype is rescued by overexpression of wild-type Dmel\MED16, but not by transgenic alleles bearing a disease-implicated variant likely to represent a full loss of function in human patients. Survivors expressing either disease-implicated variant exhibit shortened lifespans.

[updated Aug. 2026 by FlyBase; FBrf0222196]

Disease Summary Information
Disease Summary: Guillouet-Gordon syndrome
OMIM report

[GUILLOUET-GORDON SYNDROME; GGNS](https://omim.org/entry/621220)

Human gene(s) implicated

[MEDIATOR COMPLEX SUBUNIT 16; MED16](https://omim.org/entry/604062)

Symptoms and phenotype

Guillouet-Gordon syndrome (GGNS) is an autosomal recessive disorder with multiple congenital anomalies and impaired intellectual development. Intellectual disability, speech delay, and motor delay of variably severity are constant features and are associated with variable combinations of craniofacial defects, anomalies of the extremities, and heart defects (summary by Guillouet et al., 2025, pubmed:40081376). [from MIM:621220; 2026.08.05]

(OMIM, 2013-)
Genetics

Guillouet-Gordon syndrome (GGNS) is caused by homozygous or compound heterozygous mutation in the MED16 gene on chromosome 19p13. [from MIM:621220; 2026.08.05]

(OMIM, 2013-)
Cellular phenotype and pathology
Molecular information

MED16 encodes Mediator complex subunit 16, a transcription coactivator that participates in RNA polymerase II-dependent transcription. It enables nuclear thyroid hormone receptor binding activity and functions within the core Mediator complex, linking transcriptional regulation to gene expression. The protein localizes to the nucleus, nucleoplasm, and nucleolus, with additional localization reported at membranes. (GeneCards)

(FlyBase Curators, 2013-)
External links
Disease synonyms
GGNS
Ortholog Information
Human gene(s) in FlyBase
    Human gene (HGNC)
    Symbol / Name
    MED16; mediator complex subunit 16
    D. melanogaster ortholog (based on DIOPT)
    Dmel\MED16
    (DIOPT, 2013-)
    Comments on ortholog(s)

    One to one (1 human to 1 Drosophila); WDR45 has one high-scoring Drosophila ortholog, MED16.

    Other mammalian ortholog(s) used
      D. melanogaster Gene Information (1)
      Dmel\MED16
      Gene Snapshot
      Contributions welcome
      Molecular function (GO)
      Cellular component (GO)
      Gene Groups / Pathways
      Comments on ortholog(s)

      High-scoring ortholog of human MED16 (1 Drosophila to 1 human).

      Orthologs and Alignments from DRSC
      DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
      H. sapiens (Human)
      Other Genes Used: Viral, Bacterial, Synthetic (0)
        Summary of Physical Interactions (32 groups)
        MED16
        protein-protein
        Interacting group
        Assay
        References
        MED16 - Bap60
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - boca
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Cdk8
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - CG3008
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - CG17002
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - CG34159
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Cpsf6
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Dif
        pull down, autoradiography
        (Kim et al., 2004)
        MED16 - dsh
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - ebi
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Gtpbp2
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - ix
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED4
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED6
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED7
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED8
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED10
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED11
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED14
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED15
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED17
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED18
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED20
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED23
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - MED30
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - mor
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Pa1
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Ptip
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - Sec24AB
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - skd
        experimental knowledge based
        (Guruharsha et al., 2011)
        MED16 - usp
        anti bait coimmunoprecipitation, Identification by mass spectrometry
        (Xie et al., 2015)
        MED16 - Usp10
        experimental knowledge based
        (Guruharsha et al., 2011)
        Alleles Reported to Model Human Disease (Disease Ontology) (0 alleles)
        Alleles Representing Disease-Implicated Variants
        Genetic Tools, Stocks and Reagents
        Sources of Stocks
        Contact lab of origin for a reagent not available from a public stock center.
        Bloomington Stock Center Disease Page
        Related mammalian, viral, bacterial, or synthetic transgenes
        Allele
        Transgene
        Publicly Available Stocks
        Selected Drosophila transgenes
        Allele
        Transgene
        Publicly Available Stocks
        RNAi constructs available
        Allele
        Transgene
        Publicly Available Stocks
        MED16GD4275
        P{GD4275}
        w1118; P{GD4275}v14916/CyO
        MED16HMS00978
        P{TRiP.HMS00978}
        y1 sc* v1 sev21; P{TRiP.HMS00978}attP2
        MED16NIG.5465R
        P{NIG.5465R}
        P{NIG.5465R}1
        Selected Drosophila classical alleles
        Allele
        Allele class
        Mutagen
        Publicly Available Stocks
        References (4)