Hidetaka Watanabe

CTCF deletion syndrome: clinical features and epigenetic delineation

Background Heterozygous mutations in CTCF have been reported in patients with distinct clinical features including intellectual disability. However, the precise pathomechanism underlying the phenotype remains to be uncovered, partly because of the diverse function of CTCF. Here we describe extensive clinical and genetic investigation for two patients with a microdeletion encompassing CTCF. Methods We performed genetic examination including comprehensive investigation of X chromosome inactivation and DNA methylation profiling at imprinted loci and genome-wide. Results Two patients showed comparable clinical features to those in a previous report, indicating that haploinsufficiency of CTCF was the major determinant of the microdeletion syndrome. Despite the haploinsufficiency of CTCF, X chromosome inactivation was normal. DNA methylation at imprinted loci was normal, but hypermethylation at CTCF binding sites was demonstrated, of which PRKCZ and FGFR2 were identified as candidate genes. Conclusions This study confirms that haploinsufficiency of CTCF causes distinct clinical features, and that a microdeletion encompassing CTCF could cause a recognisable CTCF deletion syndrome. Perturbed DNA methylation at CTCF binding sites, not at imprinted loci, may underlie the pathomechanism of the syndrome.

Transconjunctival Approach for Zygomatic Fracture: A Single Surgeon’s Experience of More Than 20 Years

Background: To let experts evaluate a single surgeon’s experience with a combined transconjunctival and intraoral upper vestibular approach in the repair of zygomatic fractures encountered in 46 East Asian patients whom he treated over the past 20 years. Methods: Patients were identified from a database, and a retrospective case note review was conducted. A total of 67 conjunctival and secondary incisions were made on 46 patients for repair of zygomatic fractures. All operative procedures were performed using a combination of transconjunctival and intraoral upper vestibular approaches to repair zygomatic fractures. Results: The infraorbital rim and/or lateral buttress and/or lateral orbit was stabilized with titanium miniplates in 28 patients and absorbable miniplates in 11 patients. Seven patients required only reduction technique with no need of plates. Four cases needed additional canthotomy besides a conjunctival approach. No ectropion or entropion developed in any of the patients. Complications included eyelid laceration during surgery (n = 1), herniation of the conjunctiva (n = 1), temporary pyogenic granuloma of the conjunctiva after surgery (n = 1), and temporary entropion in a secondary incision (n = 1). Conclusions: A combined transconjunctival and intraoral upper vestibular approach in repairing zygomatic fractures is simple, easy, and effective, leaving no conspicuous facial scars. It is vitally important, however, that the surgeon masters the technique of transconjunctival approach well before he has good results in East Asian patients.

A Solitary Fibrous Tumor Arising in the Perioral Region

To the Editor: Solitary fibrous tumors (SFT), uncommon mesenchymal tumors that most commonly involve the pleural cavity, are observed with increasing frequency in extrapleural locations (1–4). We report a Japanese male with a SFT arising in the perioral region. In May of 2004, this 34-year-old man was referred to our clinic for examination of a nodule in his mid-face that was first noticed in August of 2003 and then enlarged gradually. On physical examination, the tumor was a firm, approximately 1.5 cm diameter, mobile nodule covered with normal skin and located in the perioral area (Fig. 1). Lymph nodes were not palpable. A color-doppler ultrasound echogram revealed a round tumor surrounded by an area of rich blood flow. The results of hematologic and serum examinations were within normal limits. The clinical diagnosis was epidermal cyst, and the tumor was excised under local anesthesia. Histologically, the tumor was well-circumscribed (Fig. 2a). The lesion involved the subcutaneous adipose

In Situ Splitting of a Rib Bone Graft for Reconstruction of Orbital Floor and Medial Wall

In situ splitting of rib bone graft was conducted in 22 patients for the repair of orbital fracture with no other complicating fractures. A bone graft was harvested from the sixth or seventh rib in the right side. The repair of the orbital floor and medial wall was successful in all the cases. Ten patients had bone grafting to the orbital floor, eight had it done onto medial wall, and 4 onto both floor and wall after reduction. The mean length of in situ rib bone graft was 40.9 mm (range, 20–70 mm), the mean width of these was 14.9 mm (range, 8–20 mm). The bone grafting was done by one leaf for 15 cases and two leafs for 7 cases in size of defects. The technique of in situ splitting of a rib bone graft for the repair of the orbital floor and medial wall is a simple and safe procedure, easily taking out the in situ splitting of a rib, and less pain in donor site. It has proved to be an optimal choice in craniofacial reconstruction, especially the defects of orbital floor and medial wall.

Retroseptal Transconjunctival Approach for Blowout Fracture of the Orbital Floor: An Ideal Choice in East-Asian Patients

Objective: To ask experts in the field to evaluate a surgeon’s experience with a retroseptal transconjunctival approach for the repair of the orbital floor damaged by blowout fracture that the surgeon encountered in 12 East-Asian patients. Methods: Patients were identified from a database, and a retrospective case note review was conducted. A total of 12 conjunctival procedures were conducted for the repair of blowout fracture with no other complicating fractures. All operative procedures were done by transconjunctival approach alone without lateral canthotomy or any other additional approach. Results: The repair of the orbital floor was successful in all the cases. Three patients had bone grafting to the orbital floor after reduction. The mean of overall surgical time was 48.8 minutes (range, 22–85 minutes) for orbit exposure by transconjunctival approach plus reduction and bone grafting when applicable. There were 6 urgent surgeries associated with missing or entrapment of the inferior rectus muscle, and its repair took an average of 32.0 minutes (range, 22–41 minutes). Postoperative diplopia recovered at an average of 12.4 weeks (range, 0–60 weeks); in urgent cases, it took an average of 5.3 weeks (range, 0–14 weeks) before recovery. Conclusions: A retroseptal transconjunctival approach in repairing the orbital floor is a simple, easily manageable, and effective procedure, leaving no conspicuous facial scars. It has proved to be an optimal choice in blowout fracture cases, especially when there was urgency to decompress the ischemic inferior rectus muscle in as short a surgery time as possible.