Severe dystrophy in DiGeorge syndrome

We present the case history of a 3-year-old girl who was examined because of severe dystrophy.In the background,cow’s milk allergy was found,but her body weight was unchanged after eliminating milk from her diet.Other types of malabsorption were excluded.Based on nasal regurgitation and facial dysmorphisms,the possibility of DiGeorge syndrome was suspected and was confirmed by fluorescence in situ hybridization.The authors suggest a new feature associated with DiGeorge syndrome.

Genetics of congenital heart defects in DiGeorge syndrome

Background Di George syndrome（DGS） is the most common microdeletion syndrome in humans and a disorder caused by a defect in chromosome 22. Almost 80% of DGS patients manifest congenital heart defects（CHD）, which are highly variable and severe. However, the genetics of CHD in DGS remain elusive. This review concludes that the TBX1 gene plays a critical role in cardiovascular defects, involving many additional genes, such as Six1, Eya1, Fgf8, Fox, and Shh. Concerning the variable manifestations of CHD in DGS,additional modifiers have been shown of involvement, such as Wnt, MOZ, micro RNAs, VEGF, and CRK.Knowledge of the genetics underlying CHD in DGS has the potential to early detection and treatment of this disease.

Delayed diagnosis of 22q11.2 deletion syndrome in an adult Chinese lady

We report a 32 year-old Chinese lady with history of tetralogy of Fallot, presented to us with chest pain due to hypocalcemia secondary to hypoparathyroidism. With her dysmerphic facial features and intellectual disability 22q11.2 deletion was suspected and confirmed by genetic study. Clinicians should consider the diagnosis of DiGeorge syndrome in adult patient with past medical history of congenital heart disease, facial dysmorphism, intellectual disability and primary hypoparathyroidism.

Tbx1 regulates the development of zebrafish neural crest cells by retinoic acid signaling

The TBX1 gene is considered to be the most important gene in the aetiology of DiGeorge syndrome （DGS）.DGS is a human disorder characterised by a number of phenotypic features involving abnormal development of pharyngeal arches, facial dysmorphogenesis and cardiac outflow tract anomalies. Retinoic acid （RA） deficiency also produces DGS-like phenotypes. The affectd tissues in DGS are derivatives of neural crest cells （NCCs）, which originate from the border between the neural plate and non-neural ectoderm, migrate to specific destinations in the body, and generate a variety of derivatives. In our study, we have explored the hypothesis that tbxl affects NCC development in zebrafish by regulating RA signaling.

Insufficiency of Mrpl40 disrupts testicular structure and semen parameters in a murine model

Approximately 31%of patients with 22q11.2 deletion syndrome(22q11.2DS)have genitourinary system disorders and 6%of them have undescended testes.Haploinsufficiency of genes on chromosome 22q11.2 might contribute to the risk of 22q11.2DS.In this study,we used mice with single-allele deletion in mitochondrial ribosomal protein L4o(Mrpl40-)as models to investigate the function of Mrpl40 in testes and spermatozoa development.The penetrance of cryptorchidism in Mrpl40+-mice was found to be higher than that in wild-type(WT)counterparts.Although the weight of testes was not significantly different between the WT and Mrpl40+-mice,the structure of seminiferous tubules and mitochondrial morphology was altered in the Mrpl40+-mice.Moreover,the concentration and motility of spermatozoa were significantly decreased in the Mrpl4O+-mice.In addition,data-independent acquisition mass spectrometry indicated that the expression of genes associated with male infertility was altered in Mrpl40+-testes.Our study demonstrated the important role of Mrpl40 in testicular structure and spermatozoa motility and count.These findings suggest that Mrpl4o is potentially a novel therapeutic target for cryptorchidism and decreased motility and count of spermatozoa.