Date: JAN.6.2023 Summary https://doi.org/10.1093/clinchem/hvac187 The index (III-1) case evaluated in the present study was a 6-year-old girl who was born at 40 weeks of gestation following an unremarkable pregnancy. The health index was unremarkable, except for a large congenital dermal melanocytosis in the back until the age of 12 months. At that time, she experienced frequent shortness of breath, noisy breathing, and sleep disturbances. Adenoid hypertrophy was later diagnosed, and an adenoidectomy was performed. She was also referred to a genetics clinic for the evaluation of coarse features and short stature. She was the first child of a non-consanguineous couple (Fig. 1A) with no family history of similar presentations. Her parents observed abnormal gait with forward curvature of the spine, broad small hands, and limited range of motion for some joints, especially in the upper limbs. Her gross motor abilities, such as running or long-distance walking, were significantly decreased, and fine motor skills were limited. Complete Article Commentary: N.A.M. Almontashiri Commentary: T.C. Wood