CRISPRi-mediated functional analysis of lung disease-associated loci at non-coding regions.

Genome-wide association studies have identified lung disease-associated loci; however, the functions of such loci are not well understood in part because the majority of such loci are located at non-coding regions. Hi-C, ChIP-seq and eQTL data predict potential roles (e.g. enhancer) of such loci; however, they do not elucidate the molecular function. To determine whether these loci function as gene-regulatory regions, CRISPR interference (CRISPRi; CRISPR/dCas9-KRAB) has been recently used. Here, we applied CRISPRi along with Hi-C, ChIP-seq and eQTL to determine the functional roles of loci established as highly associated with asthma, cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Notably, Hi-C, ChIP-seq and eQTL predicted that non-coding regions located at chromosome 19q13 or chromosome 17q21 harboring single-nucleotide polymorphisms (SNPs) linked to asthma/CF/COPD and chromosome 11p15 harboring an SNP linked to IPF interact with nearby genes and function as enhancers; however, CRISPRi indicated that the regions with rs1800469, rs2241712, rs12603332 and rs35705950, but not others, regulate the expression of nearby genes (single or multiple genes). These data indicate that CRISPRi is useful to precisely determine the roles of non-coding regions harboring lung disease-associated loci as to whether they function as gene-regulatory regions at a genomic level.

Prenatal Diagnosis of Infantile Myofibroma with Postnatal Imaging Correlation.

Infantile myofibroma is the most common fibrous tumor in infancy. A majority of these lesions are solitary and occur in the head and neck region. Unless visceral sites are involved, the clinical course is typically benign. However, the difficulty in these cases is the differentiation of a benign myofibroma from a solitary malignant neoplasm and determination of visceral involvement. Prenatal diagnosis of this condition is rarely described in the literature, but it does indeed have a role in perinatal management. Our patient was initially identified by prenatal ultrasound with fetal MRI for further characterization of the mass. We present the case of a prenatally diagnosed solitary infantile myofibroma of the lower extremity and highlight the role of prenatal imaging in the diagnosis and treatment of this condition.

Fetal MRI of Torsed Bronchopulmonary Sequestration with Tension Hydrothorax and Hydrops in a Twin Gestation.

While bronchopulmonary sequestration typically has a benign course, this congenital lung malformation has a high mortality rate when associated with untreated in utero tension hydrothorax and hydrops. Hydrops related to bronchopulmonary sequestration is believed to result from torsion of the mass with compromise of the associated blood supply. The impaired venous return of the mass then leads to tension hydrothorax with compression of the heart and mediastinal vessels, impairing global venous return. To our knowledge, this scenario has only been described prenatally by ultrasound. We present the imaging findings of a dichorionic, diamniotic twin gestation with one fetus developing tension hydrothorax and hydrops from presumed intermittent torsion of a bronchopulmonary sequestration. This diagnosis was only able to be confirmed by MRI prior to the use of ultrasound-guided interstitial laser photocoagulation for the treatment of this anomaly.

Tracheal agenesis with tracheoesophageal fistulae: fetal MRI diagnosis with confirmation by ultrasound during an ex utero intrapartum therapy (EXIT) delivery and postdelivery MRI.

Tracheal agenesis is a rare and essentially lethal anomaly with divergent prenatal imaging findings depending on the presence or absence of a tracheoesophageal fistula. All prenatally diagnosed cases of tracheal agenesis reported to date have not had a tracheoesophageal fistula and presented with thoracoabdominal findings similar to congenital high airway obstruction syndrome. We present the case of a 32-week gestation fetus with rapid onset of polyhydramnios and no persistent findings of congenital high airway obstruction syndrome that was ultimately diagnosed with tracheal agenesis plus tracheoesophageal fistula by fetal MRI. Additionally, we present the novel uses of intraoperative US during a staged ex utero intrapartum therapy delivery and postdelivery MRI, facilitated by proximity within the neonatal ICU, to confirm diagnosis and direct patient management while minimizing unnecessary investigations.