A composition for use in a method of treating a subject who has a disease that is the result of a deficiency in a protein, wherein the composition comprises (a) at least one mRNA molecule, at least a portion of which encodes a fusion protein comprising a therapeutic protein and a polypeptide capable of binding to an Fc receptor； and (b) an administration vehicle, wherein the administration vehicle is polyethyleneimine (PEI) or a lipid nanoparticle, wherein the composition is administered to the subject by pulmonary delivery, and the disease: (a) is selected from a disorder of lysosomal storage, a metabolic disorder of the urea cycle, Pompe disease, Gaucher disease, beta-thalassemia, Huntington's disease； Parkinson's disease； muscular dystrophies (such as Duchenne and Becker)； hemophilia diseases (such as hemophilia B, hemophilia A, SMN1-related spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), GALT-related galactosemia, SLC3A1-related disorders including cystinuria, COL4A5-related disorders including syndrome of Alport deficiencies of galactocerebrosidase, adrenoleukodystrophy and X-linked adrenomyeloneuropathy； Friedreich ataxia； Pelizaeus-Merzbacher disease； tuberous sclerosis related to TSC1 and TSC2； Sanfilippo bB syndrome (MPS IIIB)； CTR1-related cystinosis； including fragile X syndrome, fragile X tremor / ataxia syndrome and fragile X premature ovarian insufficiency syndrome； Prader-Willi syndrome； hereditary hemorrhagic telangiectasia (AT)； Niemann-Pick Type C1 disease； lipofuscinosis-related diseases neuronal ceroids including neuro zero-lipofuscinosis juvenile nal (JNCL), juvenile Batten disease, Santavuori-Haltia disease, Jansky-Bielschowsky disease and PTT-1 and TPP1 deficiencies； childhood ataxia related to EIF2B1, EIF2B2, EIF2B3, EIF2B4 and EIF2B5 with hypomyelination / disappearance of white matter from the central nervous system； Type 2 episodic ataxia related to CACNA1A and CACNB4； MECP2-related disorders, including classical Rett s
