ARSB and mucopolysaccharidosis: Laboratory investigations due to suspicion of mucopolysaccharidosis included urinary GAGs at 10 months (215 mg/mmol creatinine; control < 36 mg/mmol creatinine) followed by enzymatic workup—alpha‐iduronidase(18.1 nmol/spot*20 hr; Control:400–3300 nmol/spot*20 hr), beta‐galactosidase (0.52 nmol/spot*20 hr; Control:0.5–3.2 nmol/spot*20 hr), and arylsulfatase B (0.09 nmol/spot*20 hr; Control:0.15–0.9 nmol/spot*20 hr).