Genomic and genic deletions of the FOX gene cluster on 16q24.1 and inactivating mutations of FOXF1 cause alveolar capillary dysplasia and other malformations.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare, neonatally lethal developmental disorder of the lung with defining histologic abnormalities typically associated with multiple congenital anomalies (MCA). Using array CGH analysis, we have identified six overlapping microdeletions encompassing the FOX transcription factor gene cluster in chromosome 16q24.1q24.2 in patients with ACD/MPV and MCA. Subsequently, we have identified four different heterozygous mutations (frameshift, nonsense, and no-stop) in the candidate FOXF1 gene in unrelated patients with sporadic ACD/MPV and MCA. Custom-designed, high-resolution microarray analysis of additional ACD/MPV samples revealed one microdeletion harboring FOXF1 and two distinct microdeletions upstream of FOXF1, implicating a position effect. DNA sequence analysis revealed that in six of nine deletions, both breakpoints occurred in the portions of Alu elements showing eight to 43 base pairs of perfect microhomology, suggesting replication error Microhomology-Mediated Break-Induced Replication (MMBIR)/Fork Stalling and Template Switching (FoSTeS) as a mechanism of their formation. In contrast to the association of point mutations in FOXF1 with bowel malrotation, microdeletions of FOXF1 were associated with hypoplastic left heart syndrome and gastrointestinal atresias, probably due to haploinsufficiency for the neighboring FOXC2 and FOXL1 genes. These differences reveal the phenotypic consequences of gene alterations in cis.

An automated 13.5 hour system for scalable diagnosis and acute management guidance for genetic diseases.

While many genetic diseases have effective treatments, they frequently progress rapidly to severe morbidity or mortality if those treatments are not implemented immediately. Since front-line physicians frequently lack familiarity with these diseases, timely molecular diagnosis may not improve outcomes. Herein we describe Genome-to-Treatment, an automated, virtual system for genetic disease diagnosis and acute management guidance. Diagnosis is achieved in 13.5 h by expedited whole genome sequencing, with superior analytic performance for structural and copy number variants. An expert panel adjudicated the indications, contraindications, efficacy, and evidence-of-efficacy of 9911 drug, device, dietary, and surgical interventions for 563 severe, childhood, genetic diseases. The 421 (75%) diseases and 1527 (15%) effective interventions retained are integrated with 13 genetic disease information resources and appended to diagnostic reports ( https://gtrx.radygenomiclab.com ). This system provided correct diagnoses in four retrospectively and two prospectively tested infants. The Genome-to-Treatment system facilitates optimal outcomes in children with rapidly progressive genetic diseases.

Cisapride disposition in neonates and infants: in vivo reflection of cytochrome P450 3A4 ontogeny.

BACKGROUND: Cisapride, a prokinetic agent and substrate for cytochrome P450 (CYP) 3A4, has been used to treat neonates and infants with feeding intolerance and apnea or bradycardia associated with gastroesophageal reflux. At age 1 month, CYP3A4 activity has been reported to be only 30% to 40% of adult activity. This known developmental delay in the expression of CYP3A4 prompted us to conduct a classical open-label pharmacokinetic study of cisapride in neonates and young infants. METHODS: A total of 35 infants with a postconceptional age of 28 to 54 weeks at the time of the study received a single oral cisapride dose (0.2 mg/kg) at a postnatal age of 4 to 102 days, followed by repeated (n = 7) blood sampling over a 24-hour period. Cisapride and norcisapride were quantitated from plasma by HPLC-tandem mass spectrometry and pharmacokinetic data determined (n = 32) by noncompartmental methods. RESULTS: The pharmacokinetic parameters (mean +/- SD) were as follows: time to reach peak plasma concentration (t(max)), 4.4 +/- 2.8 hours (range, 0.9-12 hours); peak plasma concentration (C(max)), 29.3 +/- 16.6 ng/mL (range, 5.2-71.7 ng/mL); elimination half-life (t(1/2)), 10.7 +/- 3.7 hours (range, 1.9-18.1 hours); apparent total body clearance (Cl/F), 0.62 +/- 0.43 L. h(-1). kg(-1) (range, 0.2-1.9 L. h(-1). kg(-1)); and apparent volume of distribution (VD(ss)/F), 9.0 +/- 7.1 L/kg (range, 2.2-30.5 L/kg). The apparent renal clearance (CL(R)) of cisapride in infants (n = 28) was estimated to be 0.003 +/- 0.003 L. h(-1). kg(-1). Substratification of the population based on postconceptional age demonstrated the following findings for cisapride: (1) The mean (+/-SD) C(max) for cisapride was higher in the oldest postconceptional age category (44.5 +/- 19.6 ng/mL) than the middle and youngest categories (23.4 +/- 11.7 ng/mL and 30.0 +/- 17.5 ng/mL, respectively); (2) the t(max) for cisapride was shortest in the oldest postconceptional age category (2.2 +/- 1.1 hours) compared with the middle and youngest categories (4.4 +/- 3.3 hours and 5.0 +/- 2.6 hours, respectively); (3) the CL/F for cisapride in the youngest postconceptional age group was significantly lower (0.45 +/- 0.26 L. h(-1). kg(-1), P <.05) than in the middle and oldest categories (0.75 +/- 0.46 L. h(-1). kg(-1) and 0.85 +/- 0.69 L. h(-1). kg(-1), respectively); (4) a positive linear correlation was found between postconceptional age and the apparent terminal elimination rate constant (lambda(z)) for cisapride (P <.001, r(2) = 0.47) but not with CL/F. For norcisapride, the mean apparent C(max) was highest and the t(max) was shortest in the oldest postconceptional age group, although no association between postconceptional age and the norcisapride/cisapride area under the curve ratio was observed. All infants tolerated a single dose of cisapride well without significant alteration in QTc. CONCLUSIONS: (1) In neonates and infants, cisapride absorption and metabolism to its primary metabolite, norcisapride, were developmentally dependent; (2) approximately 99% of cisapride CL/F in neonates and young infants was nonrenal in nature; (3) CL/F of cisapride in neonates and infants noted in this study was reduced compared with data from older children and adults, likely as a result of developmental reductions in CYP3A4 activity; (4) as reflected by the correlation between postconceptional age and lambda(z), a rapid increase in total CYP3A4 activity occurs in the first 3 months of life.

A multicenter, randomized, controlled trial comparing Surfaxin (Lucinactant) lavage with standard care for treatment of meconium aspiration syndrome.

OBJECTIVE: Infants with meconium aspiration syndrome (MAS) have marked surfactant dysfunction. Airways and alveoli of affected neonates contain meconium, inflammatory cells, inflammatory mediators, edema fluid, protein, and other debris. The objective of this study was to compare treatment with bronchoalveolar lavage using dilute Surfaxin with standard therapy in a population of newborn infants with MAS. METHODS: Inclusion criteria were 1) gestational age > or =35 weeks, 2) enrollment within 72 hours of birth, 3) diagnosis of MAS, 4) need for mechanical ventilation, and 5) an oxygenation index > or =8 and < or =25. Subjects were randomized to either lavage with Surfaxin or standard care (2:1 proportion). In lavaged infants, a volume of 8 mL/kg dilute Surfaxin (2.5 mg/mL) was instilled into each lung over approximately 20 seconds followed by suctioning after 5 ventilator breaths. The procedure was repeated twice. The third and final lavage was with a more concentrated solution (10 mg/mL) of Surfaxin. RESULTS: Twenty-two infants were enrolled (15 Surfaxin and 7 control). Demographic characteristics were similar. There were trends (not significant) for Surfaxin-lavaged infants to be weaned from mechanical ventilation earlier (mean of 6.3 vs 9.9 days, respectively), as well as to have a more rapid decline in their oxygenation indexes compared with control infants, the latter difference persisting for the 96-hour-long study period. The therapy was safe and generally well tolerated by the infants. CONCLUSIONS: Dilute Surfaxin lavage seems to be a safe and potentially effective therapy in the treatment of MAS. Data from this investigation support future prospective, controlled clinical trials of bronchoalveolar lavage with Surfaxin in neonates with MAS.