ation ▁ ▁Child ▁ne uro log y ▁consult ation ▁ ▁O ph th alm ology ▁evaluation ▁ ▁Gast ro enter ology ▁ ▁Mus cul os ke let al ▁evaluation ▁ ▁C lin ical ▁gen etic ist ▁ ▁D iffer ential ▁diagn osis ▁ ▁D iffer ential ▁diagn osis ▁includes ▁Angel man ▁synd rome , ▁R ett ▁synd rome ▁and ▁M ow at – Wil son ▁synd rome . ▁ ▁Angel man ▁synd rome ▁most ▁closely ▁res emb les ▁P TH S . ▁Both ▁have ▁absent ▁speech ▁and ▁a ▁" h appy " ▁disposition . ▁One ▁thing ▁they ▁do ▁not ▁have ▁in ▁common ▁is ▁fa cial ▁ab normal ities . ▁Of ▁the ▁differential s , ▁R ett ▁synd rome ▁is ▁the ▁least ▁close ▁to ▁P TH S . ▁This ▁synd rome ▁is ▁seen ▁as ▁a ▁progress ive ▁en ce phal op ath y . ▁M ow at – Wil son ▁synd rome ▁is ▁seen ▁in ▁early ▁inf ancy ▁and ▁is ▁character ized ▁by ▁distinct ive ▁fa cial ▁ab normal ities . ▁ ▁Tre at ment ▁ ▁Currently ▁there ▁is ▁no ▁specific ▁treatment ▁for ▁this ▁condition . ▁It ▁is ▁based ▁on ▁sympt om at ology . ▁Since ▁there ▁is ▁a ▁lack ▁of ▁treatment , ▁people ▁with ▁P TH S ▁use ▁behavior al ▁and ▁training ▁approaches . ▁ ▁Re comm end ations ▁for ▁development al ▁delay ▁and ▁intellectual ▁dis ability ▁in ▁the ▁U . S . ▁( may ▁differ ▁depending ▁on ▁country ): ▁▁ ▁Early ▁inter vention ▁program ▁from ▁new born ▁to ▁age ▁ 3 ▁will