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Contains fulltext : 169755.pdf (Publisher’s version ) (Open Access) EXTL3 regulates the biosynthesis of heparan sulfate (HS), important for both skeletal development and hematopoiesis, through the formation of HS proteoglycans (HSPGs). By whole-exome sequencing, we identified homozygous missense mutations c.1382C>T, c.1537C>T, c.1970A>G, and c.2008T>G in EXTL3 in nine affected individuals from five unrelated families. Notably, we found the identical homozygous missense mutation c.1382C>T (p.Pro461Leu) in four affected individuals from two unrelated families. Affected individuals presented with variable skeletal abnormalities and neurodevelopmental defects. Severe combined immunodeficiency (SCID) with a complete absence of T cells was observed in three families. EXTL3 was most abundant in hematopoietic stem cells and early progenitor T cells, which is in line with a SCID phenotype at the level of early T cell development in the thymus. To provide further support for the hypothesis that mutations in EXTL3 cause a neuro-immuno-skeletal dysplasia syndrome, and to gain insight into the pathogenesis of the disorder, we analyzed the localization of EXTL3 in fibroblasts derived from affected individuals and determined glycosaminoglycan concentrations in these cells as well as in urine and blood. We observed abnormal glycosaminoglycan concentrations and increased concentrations of the non-sulfated chondroitin disaccharide D0a0 and the disaccharide D0a4 in serum and urine of all analyzed affected individuals. In summary, we show that biallelic mutations in EXTL3 disturb glycosaminoglycan synthesis and thus lead to a recognizable syndrome characterized by variable expression of skeletal, neurological, and immunological abnormalities.

Contains fulltext : 52497.pdf (Publisher’s version ) (Open Access) Heterozygous mutations in the transcription factor gene p63 are causative for several syndromes, with ectodermal dysplasia, orofacial clefting and limb malformations as the key characteristics. Different combinations of these features are seen in five different syndromes, of which ectrodactyly, ectodermal dysplasia and cleft lip/palate syndrome (EEC) is the most common one. Mutations in p63 can also cause non-syndromic single malformations, such as split hand foot malformation (SHFM4) and isolated cleft lip (NSCL). In this article we will present an overview of diseases caused by mutations in the p63 gene and review the known pathogenic p63 gene mutations.

Reduction of 3β-acetoxy-12α,13α-epoxyoleanan-3β-yl acetate (β-amyrin acetate epoxide)(5) with lithium–ethylamine affords β-amyrin (17%), oleanane-3β,12α-diol (3; R1= R2= H)(50%) and 13α-oleanane-3β,12α-diol(6; R1= R2= H)(27%). On photolysis 3β-acetoxyoleanan-12α-yl nitrite (3; R1= Ac, R2= NO) affords the 27-oxime (10), which has been further transformed into the aldehyde (9; R1= H, R2= OH) and the corresponding lactone (11; R1R2= O). The latter had previously been identified erroneously as oleanolic lactone acetate (12; R1= Ac, R2R3= O).