The involvement of U-type dicentric chromosomes in the formation of terminal deletions with or without adjacent inverted duplications.

An inverted duplication with a terminal deletion (inv-dup-del) is one of the complex constitutional structural rearrangements that can occur in a chromosome. Although breakages of dicentric chromosome have been suggested, the precise mechanism of this is yet to be fully understood. In our present study, we investigated the genomic structure of 10 inv-dup-del cases to elucidate this mechanism. Two recurrent 8p inv-dup-del cases harbored a large copy-number-neutral region between the duplication and deletion in common. Although the other non-recurrent cases did not appear to have this copy-number-neutral region, refined sequencing analysis identified that they contained a small intervening region at the junction between the inverted and non-inverted segment. The size of this small intervening region ranged from 1741 to 3728 bp. Combined with a presence of microhomology at the junction, a resolution of the replication fork stalling through template switching within the same replication fork is suggested. We further observed two cases with mosaicism of the dicentric chromosome and various structural rearrangements related to the dicentric chromosome. Refined analysis allowed us to identify different breakpoints on the same chromosome in the same case, implicating multiple rounds of U-type formation and its breakage. From these results, we propose that a replication-based mechanism generates unstable dicentric chromosomes and that their breakage leads to the formation of inv-dup-dels and other related derivative chromosomes.

Cervical pessary plus vaginal progesterone versus long-term tocolysis for the prevention of preterm birth: An observational retrospective study.

OBJECTIVE: To compare cervical pessaries plus vaginal progesterone versus long-term tocolysis for preventing preterm birth for women with a short cervix. METHODS: Retrospective evaluation of women with singleton pregnancy who received cervical pessaries plus vaginal progesterone (combined group) or ritodrine hydrochloride (tocolysis group) for short cervix (≤25 mm at 20-24 weeks, or ≤20 mm at 25-34 weeks) at a general hospital in Kagoshima, Japan, 2015-2019. The primary outcome was rate of preterm birth (<36 weeks); secondary outcomes were maternal hospital admittance and treatment complications. RESULTS: Data were evaluated from 95 women (combined group, n=43; tocolysis group, n=52). There was no significant difference in cervical length or gestational age at intervention between the groups. Overall, 3/43 (7.0%) women delivered before 36 weeks in the combined group versus 16/52 (30.8%) in the tocolysis group (relative risk, 0.56; 95% confidence interval, 0.41-0.76; P=0.004). Median maternal admittance was shorter in the combined group (6.6 vs 41.0 days, P<0.001). Although 36/43 (83.7%) women in the combined group reported increased vaginal discharge, no major complications occurred. CONCLUSION: A combination of pessaries and vaginal progesterone reduced the rate of preterm birth (<36 weeks) for women with short cervix as compared with long-term tocolysis.

An autopsy case of epignathus (immature teratoma of the soft palate) with intracranial extension but without brain invasion: case report and literature review.

BACKGROUND: Epignathus is a rare congenital orofacial teratoma infrequently associated with intracranial extension. Intracranial extension of an epignathus indicates a poor prognosis; however, only a small number of such cases have been reported. While there have been some studies reporting cases of epignathus expanding directly into the cranium, others have reported no communication between an epignathus and an intracranial tumor. CASE PRESENTATION: A fetus at gestational week 27 was suspected of having an epignathus with intracranial tumor as shown by ultrasonographic and magnetic resonance imaging. The fetus was stillborn and an autopsy was performed. An epignathus measuring 12 × 6 × 6 cm and weighing 270 g protruded from the mouth, with its base on the soft palate. An intracranial tumor weighing 14 g was located at the middle intracranial fossa and connected to the epignathus through the right side of the sella turcica. The intracranial tumor was encapsulated, and there was no invasion into the brain. Histologically, both the epignathus and intracranial tumor were immature teratomas, with neural and pulmonary components that were especially immature as compared to those of the internal organs and brain tissues of the fetus. CONCLUSION: There have been several reports of epignathus and intracranial tumors that did not communicate; therefore, careful evaluation is needed when a fetus is suspected of having an epignathus extending into an intracranial lesion. Our case supports the findings that an epignathus can directly expand into the cranium. Moreover, this is a rare case of an epignathus in which the intracranial lesion was encapsulated and did not invade the brain. These rare but important findings will provide additional, potential therapeutic strategies for gynecologists, neurosurgeons, and pathologists.