Childhood Apraxia of Speech is rare. Current estimates suggest that it affects around 1 in 1,000 children (
Source: MCRI). Because it's uncommon, and because from a distance it can look similar to an everyday speech delay, it's genuinely easy for it to be missed, or put down to something a child will simply grow out of.
It's different from most speech difficulties in one important way. It isn't caused by weak muscles, confusion about language, or shyness. Children with CAS usually know what they want to say. They may be able to move their lips, tongue and jaw well for eating and facial expressions for eating or pulling a face. The difficulty sits in the brain reliably planning and sequencing the specific movements speech needs, word by word, every time. That's why the same word can come out sounding different each time it's said.
Unlike many speech delays, CAS doesn't resolve by itself, and it's considered a lifelong condition. That's not a bleak outlook — it just means the therapy needs to be built for how CAS actually works, and tends to go better the sooner it starts.