LAUSR

Wewould like to thankDrs. Finsterer and Zarrouk-Mahjoub for their additional comments [1] on our case report [2]. In their additional comments, they remain skeptical about the causality of FKTNmutations for left ventricular noncompaction (LVNC) in our Fukuyama congenital muscular dystrophy (FCMD) case. We wonder if they eventually guessed that a hyper-creatine-kinase-(CK)emia is caused by FKTN mutations whereas LNVC is caused by the other gene mutation which could be inherited in an autosomal dominant fashion. In other words, they seem to assume that FCMD and isolated LVNC, both of which are rare diseases caused by respective causes, appeared coincidentally in this patient. Contrary to their guess, we thought that LVNC is one of a diverse spectrum of systemic features of FCMD. First, the probability of the coexistence of FCMD and isolated LVNC is estimated to be extremely low [3]. Secondly, LVNC was reported to be prevalent as one of the systemic features of muscular dystrophy [4]. Thirdly, the FCMD patient with the identical FKTN mutations (compound-heterozygous FKTN mutations of 3-kb retrotransposon insertion and p.Arg179Thr) showed the predominant cardiac involvement as one of the diverse spectrum of systemic features of FCMD [5]. Collectively, we regarded the LVNC as one of the systemic features of FCMD. For example, when we observe the LVNC in the patients with Duchenne/Becker muscular dystrophy caused by DMD mutation, we can naturally conclude that this LVNC is caused by DMD mutation. Likewise, we just claimed the causality of these FKTN mutations for LVNC in our FCMD case. Taken together, we still believe that FKTN mutation is a rare, but definite cause of LVNC at least in the FCMDpatients. Because the FCMDcaused by FTKNmutations is inherited in an autosomal recessive way, it would be right that LVNC,