Tyrosinemia type 1 in pediatric nephrology: Not always straightforward

The main clinical features of tyrosinemia type 1 usually appear in the first months of life, including fever, diarrhea, vomiting, liver involvement, growth failure, and renal proximal tubulopathy with subsequent hypophosphatemic rickets. An early diagnosis is crucial in order to provide specific management and to prevent complications. Here, we report on two cases referred primarily to pediatric nephrologists for the diagnosis of “neonatal tubulopathy” and management of “X-linked hypophosphatemia (XLH),” respectively. Our aim is to emphasize that (1) even a mixed tubulopathy can reveal tyrosinemia, and (2) tyrosinemia is a classic differential diagnosis of XLH that should not be forgotten, especially in the era of the anti-FGF23 burosumab.     

Malleostapedotomy for otosclerosis,our experience of nitinol piston on twelve patients

ObjectiveMalleostapedotomy allows to completely by-pass the incus in otosclerosis surgery. Recently its use has been rivaled by hydroxyapatite cement for cases of mild and moderate necrosis of the incus. However, it remains gold standard for cases of extensive necrosis, incus dislocation, or epitympanic fixation. Modern heat-crimping pistons make surgery easier and safer. This study focuses on our experience with this technique.MethodsRetrospective analysis of patient’s files and pre- and post-operative audiograms, for cases of surgically treated otosclerosis with malleostapedotomy.ResultsTwelve patients underwent malleostapedotomy for otosclerosis between 2011 and 2019. Amongst them there were 10 revision surgeries and 2 primary cases. 75% had incus long-process necrosis, 17% had epitympanic fixation and one had a history of incus transposition. Nine patients (75%) had closure of air-bone gap (ABG) of <10 dB (p < 0.001) and 11 (92%) had a threshold of 20 dB (p < 0.001). Mean pre-operative ABG was 31 dB (15 dB–55 dB), and mean post-operative ABG was 7 dB (0 dB–21 dB; p < 0.001). There was no sensorineural hearing loss nor any other post-operative complication.ConclusionsMalleostapedotomy is a safe and reliable technique, allowing an ABG closure comparable to conventional incus to vestibule prosthesis. It remains the preferred technique whenever the incus cannot be used.