Background:It remains unclear how thyroid surgical oncologic quality indicators (TSOQIs) are related to each other, and how to best interpret and apply these measures within the context of surgical quality assurance. We aimed to examine the relation between 3 TSOQIs: postoperative serum thyroglobulin level, 24-hour radioactive iodine uptake (RAIU) and metastatic lymph node ratio (MLNR). Methods:We conducted a retrospective review of patients who underwent total thyroidectomy for treatment of papillary thyroid cancer (PTC) performed by a single high-volume thyroid surgeon at a tertiary referral centre between 2012 and 2017. To establish the strength of correlation between pairs of quality indicators and the MACIS (metastasis, age, completeness of resection, invasion and size) prognostic score, we performed tests of normality and used the Spearman correlation coefficient to determine the correlation of nonnormal data containing outliers. Results:A total of 139 patients with PTC were included in the study. Their mean MACIS score was 5.0 (standard deviation 1.5). Fifteen patients had high-risk thyroid cancer (MACIS score > 6.99). A weak correlation was found between serum thyroglobulin level and RAIU (r(s) = 0.27, p = 0.006) and a moderate correlation was found between serum thyroglobulin level and MLNR (r(s) = 0.40 p = 0.002). A weak correlation between serum thyroglobulin level and MACIS score was also observed (r(s) = 0.20, p = 0.05). Conclusion:Based on our findings, we propose that the postoperative serum thyroglobulin level represents the quality metric that has the most clinical utility because it is measurable in all patients and also correlates with both RAIU and MLNR. With further research, surgeons seeking to evaluate the oncologic quality of thyroidectomy performed for PTC may consider applying a quality indicator to their future practice.

BSTRACT Purpose PIK3CA pathogenic variants in the PIK3CA-related overgrowth spectrum (PROS) activate phosphoinositide 3-kinase signaling, providing a rationale for targeted therapy, but no drug has proven efficacy and safety in this population. Our aim was to establish the six-month tolerability and efficacy of low-dose taselisib, a selective class I PI3K inhibitor, in PROS patients. Methods Patients over 16 years with PROS and PIK3CA pathogenic variants were included in a phase IB/IIA multicenter, open-label single-arm trial (six patients at 1 mg/day of taselisib, then 24 at 2 mg/day). The primary outcome was the occurrence of dose limiting toxicity (DLT). Efficacy outcomes were the relative changes after treatment of (1) tissue volume at affected and unaffected sites, both clinically and on imaging; (2) cutaneous vascular outcomes when relevant; (3) biologic parameters; (4) quality of life; and (5) patient-reported outcomes. Results Among 19 enrolled patients, 2 experienced a DLT (enteritis and pachymeningitis) leading to early trial termination (17 treated, 10 completed the study). No serious adverse reaction occurred in the 1 mg cohort ( n = 6). No significant reduction in affected tissue volume was observed (mean −4.2%; p = 0.81; SD 14.01). Thirteen (76.4%) participants reported clinical improvement (pain reduction, chronic bleeding resolution, functional improvement). Conclusion Despite functional improvement, the safety profile of low-dose taselisib precludes its long-term use.

Purpose To develop a comprehensive analysis framework to identify pre-messenger RNA splicing mutations in the context of rare disease.Methods We assessed ‘variants of uncertain significance’ through six in-silico prioritization strategies. Firstly, through comparison to functional analyses, we determined the precise effect on splicing of variants identified through clinical multi-disciplinary meetings. Next, we calculated the sensitivity of in-silico prioritization strategies to distinguish known splicing mutations from common variation (>2% in allele frequency in gnomAD) within relevant disease genes. These approaches defined an accurate in-silico strategy for variant prioritization, which we retrospectively applied to a large cohort of 2783 individuals who had previously received genomic testing for rare genomic disorders. We assessed the clinical impact of such prioritization strategies alongside routine diagnostic testing strategies.Results We identified 21 variants that potentially impacted splicing, and used cell based splicing assays to identify those variants which disrupted normal splicing. These findings underpinned new molecular diagnoses for 14 individuals. This process established that the use of pre-defined thresholds from a machine learning splice prediction algorithm, SpliceAI, was the most efficient method for variant prioritization, with a positive predictive value of 86%. We analysed 1,346,744 variants identified through diagnostic testing for 2783 individuals and observed that splicing variant prioritization strategies would improve clarity in clinical analysis for 15% of the individuals surveyed. Prioritized variants could provide new molecular diagnoses or provide additional support for molecular diagnosis for up to 81 individuals within our cohort.Conclusion We present an in-silico and functional analysis framework for the assessment of variants impacting pre-messenger RNA splicing which is applicable across monogenic disorders. Incorporation of these strategies improves clarity in diagnostic reporting, increases diagnostic yield and, with the advent of targeted treatment strategies, can directly alter patient clinical management.Key Highlights

Background: Pathogenic variants in the BCOR gene have been identified in males with X-linked recessive microphthalmia and in females with X-linked dominant oculofaciocardiodental (OFCD) syndrome. This latter condition has previously been regarded as rare but the increased availability of genetic testing in recent years has led to the identification of a greater number of patients. Methods: We report the clinical and molecular findings in a series of 10 patients with pathogenic BCOR variants from 5 families, all seen in a single institution over a two year period. Results: We emphasize the phenotypic variability in this cohort and the diverse genetic mechanisms involved which included point mutations and deletions of BCOR as well as the occurrence of gonadal and somatic mosaicism. Conclusion: In this report we demonstrate the novel findings of four newly identified variants in BCOR associated with an OFCD phenotype, and suggest that the frequency of this condition in females presenting with congenital cataract, including unilateral cataract, is more common than anticipated. We demonstrate the utility of screening for genetic causes of congenital cataract. Although gonadal mosaicism in OFCD had previously been reported, we demonstrate the presence of somatic mosaicism where BCOR mutations may only be detected in DNA from tissues other than blood such as buccal cells.

CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype–phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.

The PI3K-AKT signalling cascade has a highly conserved role in a variety of processes including cell growth and glucose homoeostasis. Variants affecting this pathway can lead to one of several segmental overgrowth disorders. These conditions are genetically heterogeneous and require tailored, multidisciplinary involvement throughout life. Hypoglycaemia is common in other overgrowth syndromes but has been described only sporadically in association with PIK3CA and CCND2 variants. We report a cohort of 6 children with megalencephaly-capillary malformation (MCAP) and megalencephaly-polydactyly-polymicrogyria-hydrocephalus (MPPH) syndromes who developed clinically significant hypoglycaemia. Based on our findings, we suggest that segmental overgrowth patients should be screened for low blood glucose levels during childhood and there should be early specialist endocrine review in any children who develop hypoglycaemia.

A diverse range of genetic aberrations can lead to Autistic Spectrum Disorder (ASD) and many of these have been identified via Next Generation Sequencing (NGS) as part of large scale consortium studies. ASD is a phenotypically variable disorder and detailed clinical descriptions are essential to appreciate genotype-phenotype relationships. In this report, we provide a comprehensive clinical description of a child with ASD in whom a TBR1 variant was identified. We review this case in the context of the current TBR1 literature and highlight the variable spectrum of disease associated with this gene. The phenotypic information outlined within the literature is incomplete, exemplifying the limitations of massively-parallel sequencing studies with regards to clinical annotation. We suggest that future reporting of ASD variants should include standardised phenotypic descriptions. This would develop a more thorough understanding of genotype-phenotype relationship, so allowing us to better counsel and support our patients.

Lathosterolosis is a rare defect of cholesterol synthesis. Only four previous cases have been reported, two of whom were siblings. We report a fifth patient, with a relatively mild phenotype. He presented at 5 years of age with bilateral posterior cataracts, which were managed with lensectomies and intraocular lens implants. He also had learning difficulties, with a full-scale IQ of 64 at 11 years of age. His head circumference is between the 0.4th and 2nd centiles, and he has mild hypotonia and subtle dysmorphism (a high-arched palate, anteverted nostrils, long philtrum and clinodactyly of toes). The diagnosis was established after sequencing a panel of genes associated with cataracts, which revealed compound heterozygous SC5D mutations: c.479C>G p.(Pro160Arg) and c.630C>A p.(Asp210Glu). The plasma lathosterol concentration was markedly raised at 219.8 μmol/L (control range 0.53-16.0), confirming the diagnosis. The c.630C>A p.(Asp210Glu) mutation has been reported in one previous patient, who also had a relatively mild phenotype (Ho et al., JIMD Rep 12:129-134, 2014). The mutation leads to a relatively conservative amino acid substitution, consistent with some residual enzyme activity. Our patient's family did not notice any benefit from treatment with simvastatin. In summary, milder patients with lathosterolosis may present with learning difficulties, cataracts and very subtle dysmorphism. The diagnosis will be missed unless plasma sterols are analysed or relevant genes sequenced.