Myosin VIIA

Alternative Names

MYO7A
Myosin, Unconventional, Family VII, Member A
MYU7A

Length

87,028 bases

No. of Exons

No. of isoforms

Protein Name

Unconventional Myosin-VIIA

Molecular Mass

254390 Da

Amino Acid Count

2215

Genomic Location

chr11:77,128,191-77,215,240

Gene Map Locus

11q13.5

Description

MYO7A is an unconventional myosin motor protein, expressed both in retinal photoreceptors and the retinal pigmented epithelium (RPE), especially in the apical part of the cell body and in the apical processes. In the photoreceptors, MYO7A is required for the normal transport of opsin through the ciliary plasma membrane to the outer segment, and, in the RPE, it functions in the movement of melanosomes and phagosomes.

MYO7A has been implicated in the spatiotemporal regulation of the visual retinoid cycle probably by mediating light-dependent translocation of the visual cycle enzyme, RPE65. Retinas lacking MYO7A contain less of RPE65, due to increased degradation. Besides, the enzyme that is present fails to undergo light-dependent translocation and the total isomerase activity is impaired.

Epidemiology in the Arab World

View Map

Variant Name	Country	Genomic Location	Clinvar Clinical Significance	CTGA Clinical Significance	Condition(s)	HGVS Expressions	dbSNP	Clinvar
NM_000260.3:c.462C>A	Jordan	NC_000011.10:g.77156083C>A		Pathogenic	Usher Syndrome Type I	NG_009086.1:g.32820C>A; NM_000260.3:c.462C>A; NP_000251.3:p.Cys154Ter
NM_000260.3:c.834C>A	Lebanon	NC_000011.10:g.77157377C>A		Pathogenic	Usher Syndrome Type I	NG_009086.1:g.34114C>A; NM_000260.3:c.834C>A; NP_000251.3:p.Tyr278Ter
NM_000260.4:c.1541G>C	United Arab Emirates	NC_000011.10:g.77162317G>C	Uncertain Significance	Uncertain Significance	Deafness, Autosomal Recessive 2	NG_009086.2:g.39072G>C; NM_000260.4:c.1541G>C; NP_000251.3:p.Ser514Thr	1232585465	1420150
NM_000260.4:c.1952_1953insAG	Iraq	chr11:77174772-77174773	Likely Pathogenic	Pathogenic	Deafness, Autosomal Recessive 2	NG_009086.2:g.51527_51528insAG; NM_000260.4:c.1952_1953insAG; NP_000251.3:p.Cys652fs	111033510	43165
NM_000260.4:c.223G>T	United Arab Emirates	NC_000011.10:g.77147888G>T		Likely Pathogenic	Deafness, Autosomal Recessive 2; Usher Syndrome Type I	NG_009086.2:g.24643G>T; NM_000260.4:c.223G>T; NP_000251.3:p.Asp75Tyr	1565320509
NM_000260.4:c.247C>A	United Arab Emirates	NC_000011.10:g.77147912C>A	Likely Pathogenic, Pathogenic	Uncertain Significance		NG_009086.2:g.24667C>A; NM_000260.4:c.247C>A; NP_000251.3:p.Arg83Ser	781790246	560896
NM_000260.4:c.2863G>A	Egypt	NC_000011.10:g.77181548G>A	Likely Pathogenic	Pathogenic	Usher Syndrome Type I	NG_009086.2:g.58303G>A; NM_000260.4:c.2863G>A; NP_000251.3:p.Gly955Ser	781988557	177733
NM_000260.4:c.3591_3592del	Saudi Arabia	NC_000011.10:g.77189431_77189432del	Likely Pathogenic, Pathogenic	Pathogenic	Usher Syndrome Type I	NG_009086.2:g.66186_66187del; NM_000260.4:c.3591_3592del; NP_000251.3:p.Cys1198ArgfsTer30	1555090368	228378
NM_000260.4:c.487G>A	Saudi Arabia	chr11:77156676	Pathogenic	Pathogenic	Usher Syndrome Type I	NG_009086.2:g.33431G>A; NM_000260.4:c.487G>A; NP_000251.3:p.Gly163Arg	1472566324	553070
NM_000260.4:c.5637-7_5742+8del	United Arab Emirates	NC_000011.10:g.77206090_77206210del		Likely Pathogenic	Deafness, Autosomal Recessive 2; Usher Syndrome Type I	NM_000260.4:c.5637-7_5742+8del
NM_000260.4:c.5660C>T	Palestine; United Arab...	NC_000011.10:g.77206120C>T	Likely Pathogenic, Pathogenic	Pathogenic	Deafness, Autosomal Recessive 2	NG_009086.2:g.82875C>T; NM_000260.4:c.5660C>T; NP_000251.3:p.Pro1887Leu	199606180	43295
NM_000260.4:c.578C>T	Saudi Arabia	chr11:77156767	Likely Pathogenic	Likely Pathogenic	Leber Congenital Amaurosis 1	NG_009086.2:g.33522C>T; NM_000260.4:c.578C>T; NP_000251.3:p.Thr193Ile	1188616455	500317
NM_000260.4:c.5835C>T	Lebanon; Saudi Arabia	chr11:77207381	Benign, Likely Benign		Deafness, Autosomal Recessive 3	NG_009086.2:g.84136C>T; NM_000260.4:c.5835C>T; NP_000251.3:p.Leu1945=	111033476	43302
NM_000260.4:c.6487G>A	Palestine	chr11:77213908	Pathogenic	Pathogenic	Deafness, Autosomal Recessive 2	NG_009086.2:g.90663G>A; NM_000260.4:c.6487G>A; NP_000251.3:p.Gly2163Ser	747656448	402267
NM_000260.4:c.721C>T	United Arab Emirates	NC_000011.10:g.77156990C>T	Likely Pathogenic, Pathogenic	Pathogenic	Usher Syndrome Type I	NG_009086.2:g.33745C>T; NM_000260.4:c.721C>T; NP_000251.3:p.Arg241Cys	782166819	438180

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Other Reports

Algeria

Ammar-Khodja et al. (2009) applied a systematic approach, involving haplotyping and genotyping, to depict the molecular etiology of non-syndromic deafness in 50 families and 9 sporadic cases from Algeria. One family with non-syndromic deafness carried a novel unclassified variant of unknown pathogenic effect in the MYO7A gene. Additionally, Ammar-Khodja et al. (2009) carried out a molecular diagnosis on two Usher type I families and found pathogenic mutations in the MYO7A and the PCDH15 genes.

Tunisia

Weil et al. (1997) identified a homozygous mutation in the MYO7A gene in affected members of a southern Tunisian family with autosomal recessive non-syndromic sensorineural deafness and retinal degeneration; consistent with Usher syndrome type IB.

External Links

http://www.genecards.org/cgi-bin/carddisp.pl?gene=MYO7A

Contributors

Asha Deepthi: 20.08.2024
Asha Deepthi: 22.10.2020
Sayeeda Hana: 17.06.2020
Nada Assaf: 16.06.2016
Ghazi O. Tadmouri: 29.11.2011
Ghazi O. Tadmouri: 28.11.2011
Tasneem Obeid: 19.09.2011
Ghazi O. Tadmouri: 12.09.2011

Edit History

Asha Deepthi: 20.08.2024
Asha Deepthi: 22.10.2020
Pratibha Nair: 31.08.2020
Sayeeda Hana: 04.08.2020
Sayeeda Hana: 20.07.2020
Sayeeda Hana: 17.06.2020
Pratibha Nair: 30.11.2011
Sarah Al-Haj Ali: 20.11.2004
Sarah Al-Haj Ali: 10.11.2004
Ghazi O. Tadmouri: 23.08.2004
Ghazi O. Tadmouri: 28.02.2004

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