Expanding the spectrum of PTH1R mutations in patients with primary failure of tooth eruption

Objectives

Primary failure of tooth eruption (PFE) is a rare autosomal-dominant disease characterized by severe lateral open bite as a consequence of incomplete eruption of posterior teeth. Heterozygous mutations in the parathyroid hormone 1 receptor (PTH1R) gene have been shown to cause PFE likely due to protein haploinsufficiency. To further expand on the mutational spectrum of PFE-associated mutations, we report here on the sequencing results of the PTH1R gene in 70 index PFE cases.

Materials and methods

Sanger sequencing of the PTH1R coding exons and their immediate flanking intronic sequences was performed with DNA samples from 70 index PFE cases.

Results

We identified a total of 30 unique variants, of which 12 were classified as pathogenic based on their deleterious consequences on PTH1R protein while 16 changes were characterized as unclassified variants with as yet unknown effects on disease pathology. The remaining two variants represent common polymorphisms.

Conclusions

Our data significantly increase the number of presently known unique PFE-causing PTH1R mutations and provide a series of variants with unclear pathogenicity which will require further in vitro assaying to determine their effects on protein structure and function.

Clinical relevance

Management of PTH1R-associated PFE is problematic, in particular when teeth are exposed to orthodontic force. Therefore, upon clinical suspicion of PFE, molecular DNA testing is indicated to support decision making for further treatment options.     

异落新妇甙的结构研究

从百合科菝葵属植物土茯苓(Smilaxg labra Roxb.)根茎的乙醇提取物中分得一个新的天然化合物(I),命名为异落新妇甙(isoastilbin)。根据元素分析,UV,IR,¹H-NMR,¹³C-NMR,2DNMR及FAB-MS,确定化合物I的结构为5,7,3',5'-四羟基二氢黄酮醇-3-O-α-L-鼠李糖甙。     

Platelet turnover and kinetics in immune thrombocytopenic purpura: results with autologous 111In-labeled platelets and homologous 51Cr- labeled platelets differ

Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr- labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP.     

Bioactive asterosaponins from the starfish Culcita novaeguineae

Two new sulfated steroidal pentaglycosides（asterosaponins）,novaeguinosides Ⅰ（2） and （Ⅱ）2,along with the known regularoside B（1）were isolated from the starfish Culcita novaeguineae.Their structures were elucidated by extensive NMR techniques as well as chemical evidence.     

Congenital Mesoblastic Nephroma: Cytogenetic Comparison to Leiomyoma

We report the karyotype analysis of a congenital mesoblastic nephroma (CMN), a usually benign renal tumor occurring most commonly during early infancy. The tumor was composed of interlacing bundles of spindle-shaped cells and it displayed both the classic and cellular histologic patterns. Immunoperoxidase studies showed reactivity for vimentin and actin. The tumor cell karyotype included additional chromosomes 11 and an altered chromosome 12. Trisomy or tetrasomy of chromosome 11 is present in five of six reported cases and may represent a frequent alteration in the karyotype of the CMN. Furthermore, breakpoints in the q13-15 region of chromosome 12 are commonly seen in leiomyomas, which are histologically similar to the CMN. Thus, the karyotype described here illustrates another similarity between the two tumor types.     

Bilateral juvenile granulosa cell tumors in a 4-month-old dysmorphic infant. A clinical, histologic, and ultrastructural study

Juvenile granulosa cell tumors were encountered within bilateral cystic ovarian masses in a 4-month-old infant. The child was the product of a consanguinous pregnancy, and manifested poor growth, relative microcephaly, facial asymmetry, and a malformed left ear. There was no history of gestational drug or hormone ingestion, and no evidence of abnormal endocrine activity after birth, however, the serum alpha-fetoprotein level was mildly elevated. The tumors were well defined by sonography and there was no evidence of metastasis. Histologically, a dense proliferation of round to oval tumor cells showed considerable individual cell necrosis and frequent microcyst formation. There was no evidence of luteinization and only mild nuclear pleomorphism. Immunoperoxidase study failed to reveal alpha-fetoprotein. Ultrastructural study supported the granulosa cell nature of the tumor, but a few cells contained bundles of intracytoplasmic filaments. There has been no evidence of recurrent disease during a 16-month follow-up period, and serial alpha-fetoprotein determinations have remained in the reference range. Comparison with two previously reported bilateral juvenile granulosa cell tumors suggests that this tumor occurs in young infants, and is amenable to conservative therapy.