First, there was a thread on a Facebook group for kids with unique chromosome disorders that gave me great hope. These are as close to Matthew's peers as possible. This was the deidentified thread:
Poster 1: Has anyone’s children developed speech after the age of 5?
Poster 2: My son is an adult and as he got older his speech has developed and is still developing. He had very little speech as a child but now you can't shut him up, he's not always very clear and is hard to understand but never ever give up
Poster 3: My son, 8, had minimal speech until about 3-4, but took off about age 4, then continued to improve age 5-6. Now is mainstreamed without support and very verbal. Great at reading, hard to understand when reading aloud and gets weekly speech privately. He is 80-90% intelligible by a stranger.
Poster 5: My son about 4 or 5 when I started to think about giving up hope of his speech developing beyond the odd few words. However, now aged 10 his speech is brilliant. He can talk in sentences and his language is improving all the time.
Poster 6: My daughter learned sign language first, when she was 5 or 6. The speech came afterwards, when she was 8 or 9. She is 13 now and uses a combination of ASL and speech. Family can usually understand her, but not as understandable to strangers. But, it is CONSTANTLY improving.
Also encouraging, Matthew has started singing and verbalizing more. He imitates the tone and syllables to the song 'Click Click' by Elska. He pants when he sees a dog. He 'ooo-ooo's when we act like a train. He says "I" for "Hi" and "Bye". Overall, he has been verbalizing much more.
He wants to communicate. He uses spontaneous sign-- a car sign when he sees a car, a dog sign plus a pant when he sees a dog, a more sign when the horse stops at the fair, and so on. He will grab your hand to take you to where he wants, or point to a desire, or tap on you to get your attention.
What I want more than anything is to hear my sweet Matthew say "I love you, Mommy." But, he is still not talking. *Sigh*