A mother has faced court over the alleged murder of her seven-month-old son.

Jacinta Beth Sells briefly appeared in the Western Australian Magistrates Court on Wednesday.

The 31-year-old allegedly murdered her son in the early hours of Monday at the family’s home in the suburb of Balcatta, in Perth’s northern suburbs.

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Police and paramedics were called to the residence about 3am following reports of a serious assault.

The lifeless infant was found with critical injuries and declared dead at the scene.

It is believed the boy suffered stab wounds and Sells was drug-affected.

He is understood to have died in front of family members, including a 13-year-old girl.

A slight woman with long dark hair and a gaunt face, Sells sat motionless in the dock with her head down, flanked by two security guards, before the brief hearing.

She stood when the charge against her was read, acknowledging she understood the accusation before being led from the court.

WA Police Commissioner Col Blanch previously described the incident as “horrific” and a “very sad story”.

Sells was remanded in custody to reappear in Stirling Garden Magistrates Court on August 20.

If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au.

In an emergency, call 000.