Efficiently selecting single row from a select with window functions row_number, lag and lead

I would like to do the following:

select id, row_number() over w as rownum, lag(id, 1) over w as prev,
lead(id, 1) over w as next from route where id=1350 window w as (order by
shortname, id asc rows between 1 preceding and 1 following) order by
shortname, id ;

However this gives the result
1350;1;;

The following query gives the result I am expecting

select * from (select id, row_number() over w as rownum,
lag(id, 1) over w as prev, lead(id, 1) over w as next
from route window w as (order by shortname, id
rows between 1 preceding and 1 following) order by shortname, id) as s
where id=1350

1350;3;1815;1813

The explain plan is
"Subquery Scan on s (cost=0.14..15.29 rows=1 width=32)"
" Filter: (s.id = 1350)"
" -> WindowAgg (cost=0.14..13.51 rows=143 width=12)"
" -> Index Only Scan using route_idx on route (cost=0.14..10.29
rows=143 width=12)"

as it makes use of the index created as follows

CREATE INDEX route_idx
ON route
USING btree
(shortname COLLATE pg_catalog."default", id);

I believe that the index has all the data that is needed to obtain the
results in a single query.
Is it possible to write the query as a single select and if so how?

Thanks in advance

Andrew Bailey