Cytochrome P450 oxidoreductase deficiency in an infant / 中华围产医学杂志

This study reported the diagnosis and treatment of cytochrome P450 oxidoreductase deficiency (PORD) in a male infant. The patient was admitted to Children's Hospital Affiliated to Shandong University at the age of 38 days due to nasal obstruction and feeding difficulties presented at 10 d after birth, as well as less weight gain. Physical examination showed craniosynostoses, hand and foot deformities, and normal external genitalia. Laboratory examination revealed mildly elevated serum adrenocorticotrophic hormone and decreased level of baseline cortisol. A homozygous mutation of c.1370G>A(p.R457H) in POR gene was detected by whole-exome sequencing, which confirmed the diagnosis of PORD. Skeletal deformities complicated by external genital malformations and/or adrenocortical hormone abnormalities are important diagnostic indicators for PORD.

A case of Antley-Bixler syndrome caused by novel POR mutations / 中华医学遗传学杂志

Objective@#To explore the genetic basis for a child affected with multiple malformations.@*Methods@#Genomic DNA was extracted from peripheral blood samples from the child and her parents. Tro whole exome sequencing and bioinformatics analysis were carried out. Suspicted mutations were verified by PCR and Sanger sequencing.@*Results@#The patient, a 2-year-old girl, presented with multiple malformations including dysmorphism, skeletal malformations and ambigulous genitalia. Through genetic testing, she was diagnosed with Antley-Bixler syndrome caused by compound heterozygous mutations of the POR gene (c.919G>T and c. 1615G>A), which were derived from her mother and father, respectively.@*Conclusion@#The compound heterozygous mutations of the POR gene probably underlie the Antley-Bixler syndrome in this patient.

Two cases of Antley-Bixler syndrome caused by mutations in different genes, FGFR2 and POR

Antley-Bixler syndrome (ABS) is a rare form of syndromic craniosynostosis with additional systemic synostosis, including radiohumeral or radioulnar synostosis. Another characteristic feature of ABS is mid-facial hypoplasia that leads to airway narrowing after birth. ABS is associated with mutations in the FGFR2 and POR genes. Patients with POR mutations present with either skeletal manifestations or congenital adrenal hyperplasia with ambiguous genitalia. We report here two cases of ABS caused by mutations in FGFR2 and POR. Although the patients had craniosynostosis and radiohumeral synostosis in common and cranioplasty was performed in both cases, the male with POR mutations showed an elevated level of 17α-hydroxyprogesterone during newborn screening and was diagnosed with congenital adrenal hyperplasia by adrenocorticotropic hormone stimulation. This patient has been treated with hydrocortisone and fludrocortisone. He had no ambiguous genitalia but had bilateral cryptorchidism. On the other hand, the female with the FGFR2 mutation showed severe clinical manifestations: upper airway narrowing leading to tracheostomy, kyphosis of the cervical spine, and coccyx deformity. ABS shows locus heterogeneity, and mutations in two different genes can cause similar craniofacial and skeletal phenotypes. Because the long-term outcomes and inheritance patterns of the disease differ markedly, depending on the causative mutation, early molecular genetic testing is helpful.

Genetic Syndromes Associated with Craniosynostosis

Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures. It leads not only to secondary distortion of skull shape but to various complications including neurologic, ophthalmic and respiratory dysfunction. Craniosynostosis is very heterogeneous in terms of its causes, presentation, and management. Both environmental factors and genetic factors are associated with development of craniosynostosis. Nonsyndromic craniosynostosis accounts for more than 70% of all cases. Syndromic craniosynostosis with a certain genetic cause is more likely to involve multiple sutures or bilateral coronal sutures. FGFR2, FGFR3, FGFR1, TWIST1 and EFNB1 genes are major causative genes of genetic syndromes associated with craniosynostosis. Although most of syndromic craniosynostosis show autosomal dominant inheritance, approximately half of patients are de novo cases. Apert syndrome, Pfeiffer syndrome, Crouzon syndrome, and Antley-Bixler syndrome are related to mutations in FGFR family (especially in FGFR2), and mutations in FGFRs can be overlapped between different syndromes. Saethre-Chotzen syndrome, Muenke syndrome, and craniofrontonasal syndrome are representative disorders showing isolated coronal suture involvement. Compared to the other types of craniosynostosis, single gene mutations can be more frequently detected, in one-third of coronal synostosis patients. Molecular diagnosis can be helpful to provide adequate genetic counseling and guidance for patients with syndromic craniosynostosis.

Anesthetic management of a neonate with Antley-Bixler syndrome: A case report

Antley-Bixler syndrome is a congenital anomaly of multiple bones and cartilage, and this was first reported by Antley and Bixler in 1975. It is characterized by craniosynostosis, midface hypoplasia with choanal stenosis and atresia, radiohumeral synostosis and femoral bowing. This is sometimes accompanied by cardiac, renal, gastrointestinal and genital malformations. The risk of respiratory distress is high in the infants with this syndrome, and this is most commonly caused by choanal stenosis and atresia. Careful anesthetic management is needed for these infants because of the potential risk of a difficult airway and respiratory complications. We report here on our experience with the anesthetic management of a neonate with Antley-Bixler syndrome and we review the relevant literature.

A Case of Antley-Bixler Syndrome

Antley-Bixler syndrome is a very rare disese of characteristic feature of craniosynostosis, brachycephaly, midface hypoplasia, depressed nasal bridge, radiohumeral synostosis and bowing femur. We presented a case of Antley-Bixtler syndrome with brief review of lituratures.