We read with great interest the case reported by Amar et al. [1997] concerning the phenotype of the cranioectodermal syndrome. However, the case suggested to us some considerations on the phenotype. Concerning calcium homeostasis, we would like to emphasize that renal disease is probably part of the syndrome [Tsimaratos et al., 1997]. The renal involvement consists of nephronophthisis, but recent publications showed evidence that the mutation involved in nephronophthisis is not present in the Sensenbrenner syndrome-associated interstitial nephritis. As suggested by Savill et al. [1997] the outcome of this tubulointerstitial nephritis seems to be poor and of rapid evolution towards end-stage renal failure. Thus, the occurrence of abnormal calcium homeostasis should not be considered apart from the renal involvement, as it is known that both tubulointerstitial nephritis and end-stage renal failure may result in calcium abnormalities such as those described by Amar et al. [1997].
With respect to the retinal involvement, a recent review showed evidence that the occurrence of retinis pigmentosa is frequent in the Sensenbrenner syndrome. According to Eke et al. [1996], this association is not fortuitous and has to be considered as another renal-retinal manifestation. Thus, photophobia should be regarded as part of the retinal involvement secondary to retinis pigmentosa.
Concerning psychomotor development, many authors reported cases with normal intellectual development [