Several recurrent variants were identified across 10 IMDs, including PAH gene variants (c.728G>A, c.611A>G, and c.721C>T) for phenylketonuria; PAH gene variants (c.158G>A, c.721C>T, and c.728G>A) for mild hyperphenylalaninemia; SLC22A5gene variant (c.1400C>G) for PCD; MMACHC gene variants (c.609G>A, c.567dup, and c.482G>A) for MMA; ACADS gene variants (c.1055C>T and c.1130C>T) for SCADD; and ACADSB gene variant (c.923G>A) for SBCADD. The gene discussed is MMACHC; the disease is pulmonary arterial hypertension.