design: BackgroundLAMM syndrome is a rare autosomal recessive diseasenamed as Michel aplasiamicrotia and microdontia in 2007 by Tekin. It is clear the syndrome is associated with FGF3, and several mutations of the FGF3 gene in LAMM syndrome have been reported. However, there without Chinese LAMM syndrome patient reported to date. Cholesteatoma with different syndromes have been described in many cases, However, LAMM syndrome with cholesteatoma has not been previously reported.Case DescriptionWe report a 5-year-old male of FGF3 compound heterozygotes from non-consanguineous marriages, affected with labyrinthine aplasia, type I microtia and microdontia(LAMM) Syndrome. We find a novel mutation(c.155GA ,p.Thr52Arg) which have never been reported. The boy had cholesteatoma in his left ear, which never been found in the past associated with LAMM Syndrome. We did a modified radical mastoidectomy to resect the cholesteatoma. The boy recovery well after 11 months following-up, but the hearing and microdontia as the same.Conclusions: The case is the first report of Chinese LAMM syndrome, and its a novel mutation of FGF3. The otitis media and cholesteatoma will expand the manifestations in LAMM syndrome.