Genomic answers for children: Dynamic analyses of >1000 pediatric rare disease genomes

PURPOSE

This study aimed to provide comprehensive diagnostic and candidate analyses in a pediatric rare disease cohort through the Genomic Answers for Kids program.

METHODS

Extensive analyses of 960 families with suspected genetic disorders included short-read exome sequencing and short-read genome sequencing (srGS); PacBio HiFi long-read genome sequencing (HiFi-GS); variant calling for single nucleotide variants (SNV), structural variant (SV), and repeat variants; and machine-learning variant prioritization. Structured phenotypes, prioritized variants, and pedigrees were stored in PhenoTips database, with data sharing through controlled access the database of Genotypes and Phenotypes.

RESULTS

Diagnostic rates ranged from 11% in patients with prior negative genetic testing to 34.5% in naive patients. Incorporating SVs from genome sequencing added up to 13% of new diagnoses in previously unsolved cases. HiFi-GS yielded increased discovery rate with >4-fold more rare coding SVs compared with srGS. Variants and genes of unknown significance remain the most common finding (58% of nondiagnostic cases).

CONCLUSION

Computational prioritization is efficient for diagnostic SNVs. Thorough identification of non-SNVs remains challenging and is partly mitigated using HiFi-GS sequencing. Importantly, community research is supported by sharing real-time data to accelerate gene validation and by providing HiFi variant (SNV/SV) resources from >1000 human alleles to facilitate implementation of new sequencing platforms for rare disease diagnoses.

Long-term follow-up of female patients with idiopathic scoliosis treated with the Wilmington orthosis

BACKGROUND

A spinal orthosis is commonly utilized in the nonoperative treatment of idiopathic scoliosis. The purpose of this study was to evaluate the long-term radiographic and functional outcomes of female patients with idiopathic scoliosis who had completed a program of treatment with the Wilmington thoracic-lumbar spinal orthosis.

METHODS

We retrospectively reviewed the clinical records and radiographs of all female patients who had successfully completed a course of treatment with the orthosis between 1973 and 1983. Ninety-one patients met the criteria for inclusion, and fifty-five women returned for a follow-up evaluation. Their mean age was thirty-one years at the time of follow-up, which was carried out at a mean of 14.6 years after the completion of treatment. The patients were evaluated clinically and radiographically, and they each completed a comprehensive questionnaire assessing their ability to perform twenty-six activities of daily living, their overall physical appearance, the cosmetic appearance of the back, their self-image, and the severity of any back pain. The questionnaire was also administered to a control group of fifty-five women without scoliosis matched for age, number of children, and occupation.

RESULTS

Seven patients (13%) demonstrated >or=5 degrees of progression of the curve, compared with the curve at the start of treatment, after discontinuing use of the orthosis. No curve progressed >17 degrees compared with the deformity at the time of the initial treatment. There was no significant overall difference between the orthotic treatment group and the control group in terms of back pain, physical activities, functional activities (with the exception of shopping) or self-care activities. As a group, the patients reported significantly greater difficulty with selected positional activities (p = 0.007). Fifty-one (93%) of the fifty-five treated women reported no subjective deterioration in their physical appearance, the cosmetic appearance of the back, or their self-image in the period since they discontinued using the brace.

CONCLUSIONS

The majority of patients who successfully complete treatment with a Wilmington thoracic-lumbar spinal orthosis for idiopathic scoliosis with an initial magnitude of between 20 degrees and 45 degrees can anticipate that the curve will remain stable into middle adulthood. Any apparent correction of the curve that occurs during treatment can be expected to be lost over time, resulting in a deformity that is equal or nearly equal in magnitude to that measured at the initiation of the orthotic management. Because some patients did demonstrate some progression of the curve by the third or fourth decade of life, it is reasonable to recommend a spinal radiograph during that time to monitor the status of the curve.

Evolutionary implications of meiotic chromosome behavior, reproductive biology, and hybridization in 6x and 9x cytotypes of Andropogon gerardii (Poaceae)

Andropogon gerardii, big bluestem, has 60 and 90 chromosome cytotypes. Meiosis in the hexaploid was shown to be regular, although some secondary associations of bivalents form. Meiosis in the enneaploid (2n = 9z = 90) is irregular, leading to most gametes having unbalanced chromosome complements. Both cytotypes show considerable self-incompatibility. Cytotypes crossed freely, forming a variety of fertile euploids and aneuploids. Indistinguishable exomorphology, intermixing in natural populations, and compatibility suggest that A. gerardii is best understood as a cytotypically complex single species.