Two novel VPS33B mutations in a patient with arthrogryposis,renal dysfunction and cholestasis syndrome in China's Mainland

Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome is a rare genetic disorder and has not been described in China. We present a female infant with neonatal intrahepatic cholestasis from a Chinese family with ARC syndrome. All 23 coding exons and flanking introns of the VPS33B gene were amplified and sequenced using peripheral lymphocyte genomic DNA of the patient and her parents. Genetic testing revealed two novel mutations (c.1033delA and c.1567C>T) in the VPS33B gene. The patient is a compound heterozygote and her parents were heterozygous for each of the mutations.

Two novel mutations in the VPS33B gene in a Chinese patient with arthrogryposis,renal dysfunction and cholestasis syndrome 1:A case report

BACKGROUND The VPS33B(OMIM:608552)gene is located on chromosome 15q26.1.We found a female infant with autosomal recessive arthrogryposis,renal dysfunction and cholestasis syndrome 1(ARCS1)caused by mutation in VPS33B.The child was diagnosed with ARCS1(OMIM:208085)after the whole exome sequencing revealed two heterozygous mutations(c.96+1G>C,c.242delT)in the VPS33B gene.CASE SUMMARY We report a Chinese female infant with neonatal cholestasis disorder,who was eventually diagnosed with ARCS1 by genetic analysis.Genetic testing revealed two new mutations(c.96+1G>C and c.242delT)in VPS33B,which is the causal gene.The patient was compound heterozygous,and her parents were both heterozygous.CONCLUSION This study extends the mutational spectrum of the VPS33B gene to provide a molecular basis for the etiological diagnosis of ARCS1 and for genetic counseling of the family.

Arthrogryposis multiplex congenita： classification, diagnosis, perioperative care, and anesthesia

Arthrogryposis multiplex congenita （AMC） is a rare disorder characterized by non-progressive, multiple contractures. In addition to affected extremities, patients may also present microstomia, decreased temporomandibular joint mobility. Although the etiology of AMC is unclear, any factor that decreases fetal movement is responsible for AMC. Thus, accurate diagnosis and classification are crucial to the appropriate treatment of AMC. The development of ultrasound technology has enabled prenatal diagnosis. Very early treatment is favorable, and multidisciplinary treatment is necessary to improve the function of AMC patients. Most patients require surgery to release contracture and reconstruct joints. However, perioperative care is challenging, and difficult airway is the first concern of anesthesiologists. Postoperative pulmonary complications are common and regional anesthesia is recommended for postoperative analgesia. This review on AMC is intended for anesthesiologists. Thus, we discuss the treatment and perioperative management of patients undergoing surgery, as well as the diagnosis and classification of AMC.

Difficult airway management in children and young adults with arthrogryposis

Objective: To review current evidence and experience with anesthesia and airway management issues in children and young adults with arthrogryposis. Data sources: Review of existing world literature and description of personal experience at a center for children's orthopedic surgery and rehabilitation over 2 decades. Methods: Description of common problems and their solutions in this unusual and diverse group of patients. Results: Arthrogryposis multiplex congenital includes more than 400 conditions that lead to congenital joint contractures affecting more than one body area. Among the many causes of arthrogryposis, 50％—65％ fall into two large categories — amyoplasia and distal arthrogryposis. There is general agreement that best function in children with arthrogryposis is achieved through early mobilization of joint contractures. Children with arthrogryposis average >5 operative procedures during childhood. Anesthesia for these procedures may be complicated by limited jaw mobility and mouth opening, restricted lung development, positioning diffi-culties, difficult venous access and concerns about increased risk for malignant hyperthermia. 75％ of arthrogryposis patients do not have a difficult airway. For those with a history of airway problems or those meeting criteria for a difficult airway, careful advanced planning helps to assure safe and successful surgery. We describe several specialized techniques for endotra-cheal intubation of children with arthrogryposis.Conclusions: Children and young adults with arthrogryposis are a diverse group. Many pose un-ique challenges for airway and surgical management. Review of individual anesthesia records and careful advanced planning by a coordinated, experienced airway team can lead to best outcomes from arthrogryposis surgery.

ARC syndrome with high GGT cholestasis caused by VPS33B mutations

Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome (OMIM 208085) is an autosomal recessive disorder that is caused by mutations in 2 interacting genes VPS33B and VIPAS39. Mutations in VPS33B gene account for most cases of ARC. As low or normal gamma-glutamyl transpeptidase (GGT) activity has been described in all patients with ARC syndrome identified so far, ARC syndrome is a possible diagnosis for low GGT cholestasis. Here we describe a Chinese patient with neonatal cholestasis and a high GGT level in three consecutive tests. She had other typical manifestations of ARC syndrome, including arthrogryposis multiplex congenita, renal involvement and ichthyosis. Genetic study of the VPS33B gene further confirmed the diagnosis by identification of compound heterozygosity of two known disease-causing mutations, c.403+2T > A and c.1509-1510insG. The mechanism of high GGT in this patient is unclear. Nevertheless, this case indicates that ARC syndrome cannot be excluded from the differential diagnosis of neonatal cholestasis even if high GGT activity is found.