4th March 2024

A 3-year-old girl presented to the genetics clinic after the neurologist saw her

A 3-year-old girl presented to the genetics clinic after the neurologist saw her. She had normal development up to 2 years of age. From the age of 2 years, she gradually began to lose her speech and fine motor skills with increasing loss of vocabulary and inability to perform pincer grips. She was noted to drop items frequently. She also developed a broad-based gait and frequently showed repetitive hand movements, including clapping and tapping her hands. Her mother notes that she would frequently shout and scream without a clear cause for this. Examination reveals a height, weight and head circumference within the 5ᵗʰ centile for growth (previously on the 75ᵗʰ centile).

Which of the following could explain her presentation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.