For basic searches, simply enter the terms in the search box and click the 'Search' button:

duchenne muscular dystrophy

The search engine will search for them in any order, ranking the entries containing all the terms higher than entries containing some of the terms.

Searches are case-insensitive, so a search for 'duchenne', 'Duchenne', or 'DUCHENNE' will return the same entries.

Adding a '+' (plus) operator before specific terms will ensure that these appear in the entries returned:

+duchenne +muscular dystrophy

The returned entries will contain the terms 'duchenne' and 'muscular', but may or may not contain the term 'dystrophy'.

Conversely, you can affix a '-' (minus) operator to a term if you want to exclude entries that contain it:

+muscular +dystrophy -duchenne

The returned entries will contain the terms 'muscular' and 'dystrophy', but will not contain the term 'duchenne'.

You can search for phrases by adding quotation marks at both ends of the phrase:

"duchenne muscular dystrophy"

Only entries containing the phrase "duchenne muscular dystrophy" will be returned.

You can also combine the '-' operator described above with phrase searches, so the search:

"muscular dystrophy" -"duchenne gene"

will return entries that contain the phrase "muscular dystrophy" but do not contain the phrase "duchenne gene".

Two wildcard operators are supported: the '?' (question mark), which is used for single-character wildcard searches, and '*' (star), which is used for multiple-character wildcard searches. For example:

dystroph*

will return entries that contain 'dystrophia', 'dystrophin', 'dystrophic', 'dystrophy', etc...

And:

dystrophi?

will return entries that contain 'dystrophia', 'dystrophin', 'dystrophic', etc., but will not return 'dystrophins'.

However:

dystroph??

will return entries that contain 'dystrophia', 'dystrophin', 'dystrophic', etc., but will not return 'dystrophy'.

You can also insert the wildcard within a term, for example:

dystro*ia

or:

dystro??i?

Finally you can use leading wildcards, for example to search for hypocortisolism/hypercortisolism:

*cortisolism

or:

hy*cortisolism

This will also help for terms which can be spelt in different ways, for example to search for 3-methylglutaric acid:

*glutar*

You can search on specific fields within an entry. For example, to search only within the 'title' field you would use:

title:duchenne

Note that there cannot be any spaces between the field name, the colon, and the term.

To do a fielded search for the terms 'duchenne', 'muscular' and 'dystrophy' in the 'title' field, you could use:

title:duchenne title:muscular title:dystrophy

A more elegant way to express this is to 'group' the search using parentheses as follows:

title:(duchenne muscular dystrophy)

Note that there cannot be any spaces between the field name, the colon, and the left parenthesis.

As mentioned in the 'Basic Search' section above, this will search for the terms in any order. You can use the '+' operator to ensure that the entries contain all the terms as follows:

title:(+duchenne +muscular +dystrophy)

And to search for a phrase within a field, you would use:

title:"duchenne muscular dystrophy"

Note that the parentheses have been replaced by quotation marks and that there are no spaces between the field name, the colon, and the left quotation mark.

OMIM has many fields you can search on. These are listed further down in this document along with examples for common and complex searches.

Like most search engines, the 'AND', 'OR' and 'NOT' boolean operators are supported. For example:

duchenne AND muscular AND dystrophy

which could also be written as:

+duchenne +muscular +dystrophy

Or this search:

muscular AND dystrophy NOT duchenne

which could also be written as:

+muscular +dystrophy -duchenne

Both ways work equally well, it is a matter of personal preference.

Note that boolean operators must be in UPPER case.

It is usually a good idea to use search grouping to indicate precedence in a search containing boolean operators. For example, the search:

muscular AND dystrophy OR duchenne AND gene

could be ambiguous.

Using search groupings (using the left and right parentheses) would make the search clearer:

(muscular AND dystrophy) OR (duchenne AND gene)

Searches can be grouped to create arbitrarily complex searches:

( (muscular AND dystrophy) OR (duchenne AND gene) ) NOT (becker OR Emery-Dreifuss)

A proximity search can be used to limit the distance in words between two terms. This is done by using the '~' (tilde) operator:

"muscular dystrophy"~10

This will return entries where the terms 'muscular' and 'dystrophy' are less than 10 words apart.

Note that this distance is direction-independent, so 'muscular ... dystrophy' is the same as 'dystrophy ... muscular'.

Individual terms in a search can be boosted with respect to each other. Terms in a search have a weight of 1 by default; however, the '^' (caret) operator can be used to boost the weight of individual terms. For example:

muscular dystrophy^10

will boost the weight of the term 'dystrophy' by a factor of 10.

Searches that don't specify a field are called 'default' searches, and the table below indicates which fields are included in a 'default' search. For entries this includes all fields except for the external data fields. This search will search all fields (except the external data fields):

duchenne muscular dystrophy

Some search fields are grouped into a 'meta' search field. One of these is the 'title' search field. Searching on this field will search the preferred, alternative, and included title fields simultaneously:

title:(duchenne muscular dystrophy)

To restrict the search to only one of these fields, use 'ti_preferred', 'ti_alternative', or 'ti_included' before your search term:

ti_preferred:(duchenne muscular dystrophy)

There are a number of meta search fields, and these generally mirror the sections that make up a MIM entry.

Some search fields support a restricted vocabulary. One such field is 'status' that contains the status of an entry, whether an entry is 'live', 'moved', or 'removed'. This search would only return entries that are live:

status:live

Whereas this search would return entries that have been moved:

status:moved

Some search fields are booleans containing either 'true' or 'false' as values. One such field is 'av_exists' which is set to 'true' for entries that contain allelic variants and 'false' for entries that don't. This search would return only entries that contain allelic variants:

av_exists:true

Conversely this search would return only entries that don't contain allelic variants:

av_exists:false

Here are some example searches with an explanation of how they are interpreted:

blindness hypertelorism

Is interpreted as:

blindness OR hypertelorism

Using '+' to require terms:

+blindness +hypertelorism

Is interpreted as:

blindness AND hypertelorism

Using '-' to negate terms:

+blindness -hypertelorism

Is interpreted as:

blindness NOT hypertelorism

Using quotes for a phrase search:

"short stature"

A wide number of external identifiers are indexed in OMIM, this section described some of those.

References in OMIM are matched against PubMed and the PubMed IDs can be searched for:

ref_pubmed_id:3294410

You can search for the Approved Gene Symbol:

approved_gene_symbol:DMD

Or you can search for the NCBI Gene ID:

gene_id:1756

Clinical Disease ID searches:

clinical_disease_id:2662

Wormbase IDs are also searchable:

wormbase_id:WBGene00140105

The list of external IDs is extensive and is located at the end of the OMIM Search Fields list, in the External Data section.

Restricting searches to specific prefixes is done as follows:

duchenne AND prefix:*

duchenne AND prefix:+

duchenne AND prefix:#

duchenne AND prefix:%

duchenne AND prefix:none

Note that the external data (located at the bottom of the table) is not included in an unfielded search, so if you wanted to search for an HGNC Approved Gene Symbol, you would need to search on the 'approved_gene_symbol' field specifically:

approved_gene_symbol:MZT1