Y-craniosynostosis by premature fusion of the metopic and coronal sutures: a new nosological entity or a variety of Saethre-Chotzen syndrome?

Increased detection of genetic loci associated with risk predictors of osteoporotic fracture using a pleiotropic cFDR method

Although GWAS have been successful in identifying some osteoporosis associated loci, the findings explain only a small fraction of the total genetic variance. In this study we use a recently developed novel pleiotropic conditional false discovery rate (cFDR) method to identify novel genetic loci associated with two risk traits for osteoporotic fracture (the clinical outcome and end result of osteoporosis), Height (HT) and Femoral Neck (FNK) BMD. The cFDR method allows us to improve the detection of associated variants by incorporating any potentially shared genetic mechanisms between the two associated traits. We analyzed the summary statistics from two GWAS meta-analyses for single nucleotide polymorphisms (SNPs) that are associated with HT and FNK BMD. Using the cFDR method, we show enrichment in the identification of SNPs associated with each trait conditioned on their strength of association with the second trait. The findings revealed 18 SNPs that are associated with both HT and FNK BMD, 4 of which had not previously been reported to play a role in bone health. The novel SNPs located at KIF1B and the intergenic region between FERD3L and TWISTNB are noteworthy as these genes may be associated with processes that are functionally important in bone metabolism. By leveraging GWAS results from related phenotypes we identified several novel loci that may contribute to the proportion of variability explained for each trait, although we cannot speculate about these potential contributions to heritability based on this analysis alone.

Genetic advances in craniosynostosis

Craniosynostosis, the premature ossification of one or more skull sutures, is a clinically and genetically heterogeneous congenital anomaly affecting approximately one in 2,500 live births. In most cases, it occurs as an isolated congenital anomaly, that is, nonsyndromic craniosynostosis (NCS), the genetic, and environmental causes of which remain largely unknown. Recent data suggest that, at least some of the midline NCS cases may be explained by two loci inheritance. In approximately 25-30% of patients, craniosynostosis presents as a feature of a genetic syndrome due to chromosomal defects or mutations in genes within interconnected signaling pathways. The aim of this review is to provide a detailed and comprehensive update on the genetic and environmental factors associated with NCS, integrating the scientific findings achieved during the last decade. Focus on the neurodevelopmental, imaging, and treatment aspects of NCS is also provided.

A rare case of acrocephaly: Saethre-Chotzen syndrome or Crouzon?

Acrocephaly is a common neonatal craniofacial malformation. Saethre-Chotzen syndrome (SCS) is one of the acrocephaly related syndromes less frequently described in the literature. A female newborn term was admitted to our Neonatal Unit to study craniofacial dysmorphia without family history of interest. Pregnancy, childbirth and the neonatal period were uneventful. She had exotropia, short anterior-posterior cranial diameter, flat occiput and wide normotensive anterior fontanelle (beginning at the nose root, continuing through the sagittal suture with the posterior fontanelle) without syndactyly. The scanner imaging confirmed an acrocephaly with fusion of bilateral coronal sutures. We initially suspected a cranyosinostosis due to a Crouzon syndrome or SCS. After differential diagnosis and genetic study the patient was diagnosed as having SCS due to a de novo TWIST1 gene mutation. The craniofacial dysmorphias were corrected early by neurosurgical with good results. This case shows a new example of the phenotypic and genotypic variability of these TWIST1 gene mutations.