An alcoholic mother of eight who starved her four-year-old son to death and left his body in a cot for nearly two years has been jailed for 15 years.

Amanda Hutton, 43, was found guilty at Bradford crown court on Thursday of the manslaughter of Hamzah Khan, whose body was found in squalor at Hutton's home in Bradford in September 2011.

The judge, Roger Thomas QC, said she was being punished for her "terrible failures to fulfil the most basic responsibilities that you, as a mother, should have fulfilled". Hutton admitted neglecting five of her other children, aged between five and 13, who were living in the terrible conditions.

Her eldest son, Tariq Khan, 24, was given a two-year suspended sentence for preventing the burial of his brother. His barrister had argued in mitigation that he, too, was a victim of his mother.

The court heard that Tariq Khan told probation officers his mother held a knife to the throat of one of the children two days after Hamzah's death. His mother also threatened to burn down the house.

The judge was told that one of Hutton's neighbours alerted social services to her concerns about the family six months before Hamzah's body was found. The woman, who cannot be named, said she did this in March 2011 because of children crying and not being comforted, threatening voices towards the youngsters, blinds never being open and children not playing outside. It was "better to be safe than sorry", she said at the time.

Paul Greaney QC, prosecuting, said the details of what happened next were complex, but social services, education authorities and the police "were all involved to a greater or lesser extent". But he said this activity did not result in Hamzah's body being discovered or the other children being rescued.

He said whatever had or had not been done by the relevant agencies "should not detract from the shocking and disgraceful conduct of Amanda Hutton involving six of her children". He added: "She killed Hamzah – no one else."

Sentencing Hutton, the judge said Hamzah's manslaughter involved "failing to provide him with anything like adequate nourishment over a long period of time – in short you starved him to death". Referring to the five child cruelty charges she admitted, Thomas said these related to a period of nearly three years when "on an ever declining scale you failed your young children, causing them to live in quite appalling conditions of squalor which understandably shocked even the most seasoned police officers who attended your home in September 2011".

Thomas told Hutton she "must be regarded as a real danger to any child with whom you may live, or in any way have care of in the future".

He sentenced Hutton to 12 years in prison for manslaughter. He gave her a three-year sentence for child cruelty, to be served consecutively. He said she should serve two and a half years for preventing the lawful burial of Hamzah, to be served concurrently. A charge of fraud relating to Hutton claiming child benefit for Hamzah after his death will lie on the file.