An adolescent case of ASXL3-related disorder with delayed onset of feeding difficulty.

BACKGROUND: ASXL3-related disorder, first described in 2013, is a genetic disorder with an autosomal dominant inheritance that is caused by a heterozygous loss-of-function variant in ASXL3. The most characteristic feature is neurodevelopmental delay with consistently limited speech. Feeding difficulty is a main symptom observed in infancy. However, no adolescent case has been reported. CASE PRESENTATION: A 14-year-old girl with ASXL3-related syndrome was referred to our hospital with subacute onset of emotional lability. Limbic encephalitis was ruled out by examination; however, the patient gradually showed a lack of interest in eating, with decreased diet volume. Consequently, she experienced significant weight loss. She experienced no symptoms of bulimia, or food allergy; therefore, avoidant/restrictive food intake disorder (ARFID) was clinically suspected. CONCLUSIONS: We reported the first case of ASXL3-related disorder with adolescent onset of feeding difficulty. ARFID was considered a cause of the feeding difficulty.

Auditory Neuropathy Spectrum Disorder Progressing with Motor and Sensory Neuropathy Caused by an ATP1A1 Variant.

We encountered a 27-year-old Japanese woman with sensorineural deafness progressing to motor and sensory neuropathy. At 16 years old, she had developed weakness in her lower extremities and hearing impairment, which gradually deteriorated. At 22 years old, combined audiological, electrophysiological, and radiological examination results were consistent with auditory neuropathy spectrum disorder (ANSD). Genetic analyses identified a previously reported missense variant in the ATP1A1 gene (NM_000701.8:c.1799C>G, p.Pro600Arg). Although sensorineural deafness has been reported as a clinical manifestation of ATP1A1-related disorders, our case suggested that ANSD may underlie the pathogenesis of deafness in ATP1A1-related disorders. This case report broadens the genotype-phenotype spectrum of ATP1A1-related disorders.

Biallelic structural variations within FGF12 detected by long-read sequencing in epilepsy.

We discovered biallelic intragenic structural variations (SVs) in FGF12 by applying long-read whole genome sequencing to an exome-negative patient with developmental and epileptic encephalopathy (DEE). We also found another DEE patient carrying a biallelic (homozygous) single-nucleotide variant (SNV) in FGF12 that was detected by exome sequencing. FGF12 heterozygous recurrent missense variants with gain-of-function or heterozygous entire duplication of FGF12 are known causes of epilepsy, but biallelic SNVs/SVs have never been described. FGF12 encodes intracellular proteins interacting with the C-terminal domain of the alpha subunit of voltage-gated sodium channels 1.2, 1.5, and 1.6, promoting excitability by delaying fast inactivation of the channels. To validate the molecular pathomechanisms of these biallelic FGF12 SVs/SNV, highly sensitive gene expression analyses using lymphoblastoid cells from the patient with biallelic SVs, structural considerations, and Drosophila in vivo functional analysis of the SNV were performed, confirming loss-of-function. Our study highlights the importance of small SVs in Mendelian disorders, which may be overlooked by exome sequencing but can be detected efficiently by long-read whole genome sequencing, providing new insights into the pathomechanisms of human diseases.

A missense variant at the RAC1-PAK1 binding site of RAC1 inactivates downstream signaling in VACTERL association.

RAC1 at 7p22.1 encodes a RAC family small GTPase that regulates actin cytoskeleton organization and intracellular signaling pathways. Pathogenic RAC1 variants result in developmental delay and multiple anomalies. Here, exome sequencing identified a rare de novo RAC1 variant [NM_018890.4:c.118T > C p.(Tyr40His)] in a male patient. Fetal ultrasonography indicated the patient to have multiple anomalies, including persistent left superior vena cava, total anomalous pulmonary venous return, esophageal atresia, scoliosis, and right-hand polydactyly. After birth, craniofacial dysmorphism and esophagobronchial fistula were confirmed and VACTERL association was suspected. One day after birth, the patient died of respiratory failure caused by tracheal aplasia type III. The molecular mechanisms of pathogenic RAC1 variants remain largely unclear; therefore, we biochemically examined the pathophysiological significance of RAC1-p.Tyr40His by focusing on the best characterized downstream effector of RAC1, PAK1, which activates Hedgehog signaling. RAC1-p.Tyr40His interacted minimally with PAK1, and did not enable PAK1 activation. Variants in the RAC1 Switch II region consistently activate downstream signals, whereas the p.Tyr40His variant at the RAC1-PAK1 binding site and adjacent to the Switch I region may deactivate the signals. It is important to accumulate data from individuals with different RAC1 variants to gain a full understanding of their varied clinical presentations.

Cervical Cerclage to Prevent Intrauterine Balloon Prolapse.

Intrauterine balloon prolapse sometimes occurs, and the intrauterine balloon must be reinserted. Furthermore, intrauterine balloon tamponade (IBT) failure can necessitate additional invasive procedures. We report a case of cervical cerclage with IBT for placenta previa with a cervical dilation. In our case, emergency cesarean section was performed at 35 + 4 weeks of gestation because of persistent hemorrhage. During the operation, we performed IBT to prevent further postpartum hemorrhage. However, immediately after the operation, uterine cervical dilatation was 6 cm, which resulted in cervical dilation and prolapse of the intrauterine balloon. Therefore, we performed cervical cerclage using absorbable sutures with IBT and blood transfusion. We speculated that the intrauterine balloon might have induced cervical canal ripening during the operation. Our case suggested that cervical cerclage with IBT is a useful method to prevent intrauterine balloon prolapse in cases with cervical dilation.

Imagawa-Matsumoto syndrome: SUZ12-related overgrowth disorder.

The SUZ12 gene encodes a subunit of polycomb repressive complex 2 (PRC2) that is essential for development by silencing the expression of multiple genes. Germline heterozygous variants in SUZ12 have been found in Imagawa-Matsumoto syndrome (IMMAS) characterized by overgrowth and multiple dysmorphic features. Similarly, both EZH2 and EED also encode a subunit of PRC2 each and their pathogenic variants cause Weaver syndrome and Cohen-Gibson syndrome, respectively. Clinical manifestations of these syndromes significantly overlap, although their different prevalence rates have recently been noted: generalized overgrowth, intellectual disability, scoliosis, and excessive loose skin appear to be less prevalent in IMMAS than in the other two syndromes. We could not determine any apparent genotype-phenotype correlation in IMMAS. The phenotype of neurofibromatosis type 1 arising from NF1 deletion was also shown to be modified by the deletion of SUZ12, 560 kb away. This review deepens our understanding of the clinical and genetic characteristics of IMMAS together with other overgrowth syndromes related to PRC2. We also report on a novel IMMAS patient carrying a splicing variant (c.1023+1G>C) in SUZ12. This patient had a milder phenotype than other previously reported IMMAS cases, with no macrocephaly or overgrowth phenotypes, highlighting the clinical variation in IMMAS.

Distal arthrogryposis in a girl arising from a novel TNNI2 variant inherited from paternal somatic mosaicism.

TNNI2 at 11p15.5 encodes troponin I2, fast skeletal type, which is a member of the troponin I gene family and a component of the troponin complex. Distal arthrogryposis (DA) is characterized by congenital limb contractures without primary neurological or muscular effects. DA is inherited in an autosomal dominant fashion and is clinically and genetically heterogeneous. Exome sequencing identified a causative variant in TNNI2 [NM_003282.4:c.532T>C p.(Phe178Leu)] in a Japanese girl with typical DA2b. Interestingly, the familial study using Sanger sequencing suggested a mosaic variant in her healthy father. Subsequent targeted amplicon-based deep sequencing detected the TNNI2 variant with variant allele frequencies of 9.4-17.7% in genomic DNA derived from peripheral blood leukocytes, saliva, hair, and nails in the father. We confirmed a disease-causing variant in TNNI2 in the proband inherited from her asymptomatic father with its somatic variant. Our case demonstrates that careful clinical and genetic evaluation is required in DA.

Distal 2q duplication in a patient with intellectual disability.

We report on a patient with a distal 16.4-Mb duplication at 2q36.3-qter, who presented with severe intellectual disability, microcephaly, brachycephaly, prominent forehead, hypertelorism, prominent eyes, thin upper lip, and progenia. Copy number analysis using whole exome data detected a distal 2q duplication. This is the first report describing a distal 2q duplication at the molecular level.

Pathogenic variants detected by RNA sequencing in Cornelia de Lange syndrome.

Recent studies suggest that transcript isoforms significantly overlap (approximately 60%) between brain tissue and Epstein-Barr virus-transformed lymphoblastoid cell lines (LCLs). Interestingly, 14 cohesion-related genes with variants that cause Cornelia de Lange Syndrome (CdLS) are highly expressed in the brain and LCLs. In this context, we first performed RNA sequencing of LCLs from 22 solved (with pathogenic variants) and 19 unsolved (with no confirmed variants) CdLS cases. Next, an RNA sequencing pipeline was developed using solved cases with two different methods: short variant analysis (for single-nucleotide and indel variants) and aberrant splicing detection analysis. Then, 19 unsolved cases were subsequently applied to our pipeline, and four pathogenic variants in NIPBL (one inframe deletion and three intronic variants) were newly identified. Two of three intronic variants were located at Alu elements in deep-intronic regions, creating cryptic exons. RNA sequencing with LCLs was useful for identifying hidden variants in exome-negative cases.

The retrospective study for effectiveness of cervical cerclage in preventing recurrent preterm birth.

OBJECTIVE: This study aimed to clarify the effectiveness of cervical cerclage in preventing recurrent preterm births. MATERIALS AND METHODS: A retrospective study was conducted using the perinatal registration database of the Japan Society of Obstetrics and Gynecology for the Perinatal Center from 2014 to 2016. The efficacies of history-indicated, ultrasound-indicated, and physical examination-indicated cerclage as preventive treatments for women with a history of preterm birth were evaluated by comparing cerclage and non-cerclage cases. Fisher's exact test was performed to evaluate any significant differences in patient backgrounds. Prior to the evaluation, propensity score matching was performed for history-indicated and ultrasound-indicated cerclage patients. RESULTS: For this study, 6060 multiparous women with a history of preterm birth were reviewed. After excluding 17 patients with unknown indications for cervical cerclage, 6043 patients were included in the study. History-indicated and ultrasound-indicated cerclage did not reduce the risk of preterm birth in subsequent pregnancies for any of the pregnancy periods (p = 0.413, p = 1.000). In contrast, physical examination-indicated cerclage significantly reduced the risk of subsequent preterm births for all pregnancy periods (p < 0.001). CONCLUSION: Subsequent preterm births were effectively prevented only in physical examination-indicated cerclage cases. For history- or ultrasound-indicated cerclage, statistically significant differences in subsequent preterm births were not evident.

Two families with TET3-related disorder showing neurodevelopmental delay with craniofacial dysmorphisms.

TET3 at 2p13.1 encodes tet methylcytosine dioxygenase 3, a demethylation enzyme that converts 5-methylcytosine to 5-hydroxymethylcytosine. Beck et al. reported that patients with TET3 abnormalities in either an autosomal dominant or recessive inheritance fashion clinically showed global developmental delay, intellectual disability, and dysmorphisms. In this study, exome sequencing identified both mono- and biallelic TET3 variants in two families: a de novo variant NM_001287491.1:c.3028 A > G:p.(Asn1010Asp), and compound heterozygous variants NM_001287491.1:c.[2077 C > T];[2896 T > G],p.[Gln693*];[Cys966Gly]. Despite the different inheritance modes, the affected individuals showed similar phenotypic features. Including these three patients, only 14 affected individuals have been reported to date. The accumulation of data regarding individuals with TET3-related disorder is necessary to describe their clinical spectrum.

Retrospective study of the recurrence risk of preterm birth in Japan.

BACKGROUND: A history of preterm birth is a risk factor for preterm birth in a future pregnancy, and there are some reports of prevention methods, such as the administration of progesterone. However, the rate of recurrence of preterm birth in Japan has not been clarified, and there is no data for judging whether these preventive methods are effective. OBJECTIVE: To clarify the risk of recurrence of preterm birth and preterm prelabor rupture of membranes (pPROM) in Japan. MATERIALS AND METHODS: A retrospective study was conducted using the perinatal registration database of the Japan Obstetrics and Gynecology Society for the Perinatal Center from 2014 to 2016. There were 704,418 subjects, of which 190,990 were excluded those with unknown maternal information, those under the age of 20 years, those with perinatal disease related to preterm birth, and first-time mothers. RESULTS: Logistic model unavailable and multivariate analysis were performed. An analysis of the preterm birth history indicated the risk of preterm birth in the current pregnancy, and the odds ratio for preterm birth recurrence once, twice, and three times or more was 3.3, 6.6, and 7.8, respectively. As a secondary analysis, we analyzed whether the history of pPROM is a risk factor of recurrence of pPROM and found a significant association with an odds ratio of 3.4. CONCLUSION: Having a preterm birth history increases the risk of recurrence of preterm birth, and the risk of recurrent preterm birth increases as the number of preterm births increases. Although this report is intended for high-risk pregnancies wherein the rate of preterm birth is high, as previously reported, our data indicate that in Japan, preterm birth is a risk factor of recurrent preterm birth.

Whole exome sequencing of fetal structural anomalies detected by ultrasonography.

The objective of this study was to evaluate the efficacy of whole exome sequencing (WES) for the genetic diagnosis of cases presenting with fetal structural anomalies detected by ultrasonography. WES was performed on 19 cases with prenatal structural anomalies. Genomic DNA was extracted from umbilical cords or umbilical blood obtained shortly after birth. WES data were analyzed on prenatal phenotypes alone, and the data were re-analyzed after information regarding the postnatal phenotype was obtained. Based solely on the fetal phenotype, pathogenic, or likely pathogenic, single nucleotide variants were identified in 5 of 19 (26.3%) cases. Moreover, we detected trisomy 21 in two cases by WES-based copy number variation analysis. The overall diagnostic rate was 36.8% (7/19). They were all compatible with respective fetal structural anomalies. By referring to postnatal phenotype information, another candidate variant was identified by a postnatal clinical feature that was not detected in prenatal screening. As detailed phenotyping is desirable for better diagnostic rates in WES analysis, we should be aware that fetal phenotype is a useful, but sometimes limited source of information for comprehensive genetic analysis. It is important to amass more data of genotype-phenotype correlations, especially to appropriately assess the validity of WES in prenatal settings.

Laparoscopic Removal of Modified Vertical Uterine Compression Sutures due to Postoperative Focal Pain.

Previously we reported laparoscopic removal of compression sutures due to uterine ischemia and related pain, which has two of the difficult aspects: (1) maneuvering the curved needle to perform compression suturing in the narrow surgical field, and (2) distinguishing between the threads of the cesarean section wound sutures versus the vertical compression sutures during removal, as the threads are the same white color. We performed vertical compression sutures for intrapartum hemorrhage with total placental previa, and modified both the needle type and the color of the thread used for uterine compression sutures during cesarean section. After the operation, we performed successful laparoscopic removal of compression sutures for postoperative focal pain. Changing the needle type and color helped to perform operations. The present case supports the concept that the laparoscopic removal of uterine compression suturing is useful for controlling pain in cases where general analgesics are ineffective.