Long term follow-up after haematopoietic stem cell transplantation for mucopolysaccharidosis type I-H: a retrospective study of 51 patients.

Mucopolysaccharidosis type I-H (MPS I-H) is a rare lysosomal storage disorder caused by α-L-Iduronidase deficiency. Early haematopoietic stem cell transplantation (HSCT) is the sole available therapeutic option to preserve neurocognitive functions. We report long-term follow-up (median 9 years, interquartile range 8-16.5) for 51 MPS I-H patients who underwent HSCT between 1986 and 2018 in France. 4 patients died from complications of HSCT and one from disease progression. Complete chimerism and normal α-L-Iduronidase activity were obtained in 84% and 71% of patients respectively. No difference of outcomes was observed between bone marrow and cord blood stem cell sources. All patients acquired independent walking and 91% and 78% acquired intelligible language or reading and writing. Intelligence Quotient evaluation (n = 23) showed that 69% had IQ ≥ 70 at last follow-up. 58% of patients had normal or remedial schooling and 62% of the 13 adults had good socio-professional insertion. Skeletal dysplasia as well as vision and hearing impairments progressed despite HSCT, with significant disability. These results provide a long-term assessment of HSCT efficacy in MPS I-H and could be useful in the evaluation of novel promising treatments such as gene therapy.

Body location and tail regeneration effects on osteoderms morphology-are they useful tools for systematic, paleontology, and skeletochronology in diploglossine lizards (squamata, anguidae)?

Although diploglossine osteoderms were mentioned in several systematic and paleontological studies, their morphological variability in single specimens or within species remains paradoxically undescribed. This is mainly the effect of the lack of attention paid hitherto to the morphological and histological characteristics of the tail osteoderms. This study demonstrated that a previously undescribed morphological variability exists in these osteoderms, especially in those resulting from tail regeneration. Indeed, regenerated osteoderms display a plesiomorphic anguid morphology that was previously considered to be absent in Diploglossinae. We also provide the first histological description of diploglossine osteoderms and new information about the obvious differences in growth dynamic between regenerated and nonregenerated osteoderms. These new data raise questions about the usefulness of diploglossine osteoderms in systematic, paleontological, and skeletochronological studies. Our study shows that the exact position on the trunk or on a regenerated or nonregenerated tail of each studied osteoderm must be known in order to avoid mistakes related to their important interspecies and intraspecies variability.