A doctor omitted details of a phone conversation with the mother of a boy who died the next day to "avoid any criticism levelled against her", a medical tribunal has heard.
Ryan Morse, 12, died at home in Blaenau Gwent in December 2012.
It came hours after Joanne Rudling refused to make a home visit despite being told his genital area was "black", the hearing was told.
But Dr Rudling denies she refused to undertake the home visit.
She also denies a number of other allegations, including that on 7 December she failed to obtain an adequate history of Ryan's wellbeing and change in genitalia colour or advise that an urgent assessment was required.
Ryan's mother, Carol Morse, told the hearing that Dr Rudling said the discoloration was due to hormones.
Ms Morse added that the doctor said she should call back on the Monday to arrange an appointment with a male doctor.
The following morning Ms Morse found her son had died.
It was later determined he had died from Addison's disease.
Dr Rudling and Dr Lindsey Thomas were previously charged with manslaughter by gross negligence.
Dr Thomas's case was thrown out and a judge ruled there was no case to answer on the manslaughter charge against Dr Rudling.
Dr Rudling was also acquitted of perverting the course of justice.
On Monday, Dr Rudling faced a Medical Practitioners Tribunal in Manchester to face allegations of misconduct in relation to her treatment of Ryan.
Ms Morse described Ryan's health between July and September as "fluctuating" but throughout October he was unwell as he lost weight and the discoloration remained.
On 7 November she took him to see Dr Rudling and explained his illness and said the discoloration was "prominent".
The GP ordered blood tests but her examination, according to Mrs Morse, was "limited" and her son was not even examined on a couch.
The tribunal heard that two weeks later Dr Rudling told Ms Morse that Ryan had a virus and would continue to have symptoms for a couple of months.
On 7 December, Ms Morse rang the surgery after she noticed his genital area was black, but the doctor refused to come out for a visit, the hearing was told.
Dr Rudling accepted she did not make a contemporaneous note of the conversation and made a retrospective entry on 10 December to make it look as if it was written three days earlier, said Peter Horgan, for the General Medical Council (GMC).
He said this was dishonest behaviour and its purpose was to mislead anyone reviewing Ryan's records, which the doctor denies.
"But what the GMC also allege is that at that stage and when making that entry, the doctor, knowing and being aware of the sad death of Ryan, had failed to record that she had been told Ryan's genitals were black and she refused to undertake a home visit," Mr Horgan said.
- Adrenal gland is damaged and not enough cortisol and aldosterone are produced
- About 8,400 people in the UK have it
- Symptoms include fatigue, muscle weakness, loss of appetite and unintentional weight loss
- People can also develop small areas of darkened skin or darkened lips or gums
"Matters that should have been placed in that note.
"The doctor's failure to record that... was so as to avoid any criticism levelled against her care and treatment of Ryan."
Andrew Colman, representing Dr Rudling, put it to Mrs Morse that she had "got some things wrong", but said he was not accusing her of lying.
He suggested that Dr Rudling had examined Ryan lying down on 7 November and that Ms Morse had not mentioned skin discoloration during that consultation, but Ms Morse disagreed.
Mr Colman said Dr Rudling's recollection of the 7 December phone conversation was different and Ms Morse had asked whether the genital symptoms were due to his age, puberty or hormones.
He said Dr Rudling never refused to make a home visit but Ms Morse disagreed.
The hearing continues.