  PSR J1953+1844 (i.e., M71E) is a millisecond pulsar (MSP)in a 53 minute
binary orbit discovered by the Five-hundred-meter Aperture Spherical radio
Telescope. The mass function from pulsar timing is $2.3\times10^{-7}$
$M_\odot$. The possible redback origin of this system has been discussed by Pan
et al. We discuss here an alternative evolution track for this binary system,
namely that PSR J1953+1844 is a descendant of an ultra-compact X-ray binary
(UCXB), which has a hydrogen-poor donor accreting onto a neutron star (NS) with
an orbital period of $\leq1$ hr. We noticed that some of UCXB systems hold an
accreting millisecond X-ray pulsars (AMXPs) and a donor with a mass of about
0.01 M$_\odot$. M71E has a very similar orbit to those of AMXPs, indicating
that it might be evolved from a UCXB similar to PSR J1653--0158. The companion
star of M71E should be significantly bloated and it most probably has a carbon
and oxygen composition, otherwise a low inclination angle of the orbit is
required for a helium companion. The discovery of this M71E binary system may
shed light on when and how an NS in a UCXBs turns into a radio pulsar.
