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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., (© 2021. The Author(s).)

Congenital erythropoietic porphyria (CEP) is an inborn error of heme synthesis resulting from uroporphyrinogen III synthase (UROS) deficiency and the accumulation of nonphysiological porphyrin isomer I metabolites. Clinical features are heterogeneous among patients with CEP but usually combine skin photosensitivity and chronic hemolytic anemia, the severity of which is related to porphyrin overload. Therapeutic options include symptomatic strategies only and are unsatisfactory. One promising approach to treating CEP is to reduce the erythroid production of porphyrins through substrate reduction therapy by inhibiting 5-aminolevulinate synthase 2 (ALAS2), the first and rate-limiting enzyme in the heme biosynthetic pathway. We efficiently reduced porphyrin accumulation after RNA interference-mediated downregulation of ALAS2 in human erythroid cellular models of CEP disease. Taking advantage of the physiological iron-dependent posttranscriptional regulation of ALAS2, we evaluated whether iron chelation with deferiprone could decrease ALAS2 expression and subsequent porphyrin production in vitro and in vivo in a CEP murine model. Treatment with deferiprone of UROS-deficient erythroid cell lines and peripheral blood CD34+-derived erythroid cultures from a patient with CEP inhibited iron-dependent protein ALAS2 and iron-responsive element-binding protein 2 expression and reduced porphyrin production. Furthermore, porphyrin accumulation progressively decreased in red blood cells and urine, and skin photosensitivity in CEP mice treated with deferiprone (1 or 3 mg/mL in drinking water) for 26 weeks was reversed. Hemolysis and iron overload improved upon iron chelation with full correction of anemia in CEP mice treated at the highest dose of deferiprone. Our findings highlight, in both mouse and human models, the therapeutic potential of iron restriction to modulate the phenotype in CEP., (© 2020 by The American Society of Hematology.)

Purpose: Postzygotic activating mutations of PIK3CA cause a wide range of mosaic disorders collectively referred to as PIK3CA-related overgrowth spectrum (PROS). We describe the diagnostic yield and characteristics of PIK3CA sequencing in PROS., Methods: We performed ultradeep next-generation sequencing (NGS) of PIK3CA in various tissues from 162 patients referred to our clinical laboratory and assessed diagnostic yield by phenotype and tissue tested., Results: We identified disease-causing mutations in 66.7% (108/162) of patients, with mutant allele levels as low as 1%. The diagnostic rate was higher (74%) in syndromic than in isolated cases (35.5%; P = 9.03 × 10 -5 ). We identified 40 different mutations and found strong oncogenic mutations more frequently in patients without brain overgrowth (50.6%) than in those with brain overgrowth (15.2%; P = 0.00055). Mutant allele levels were higher in skin and overgrown tissues than in blood and buccal samples (P = 3.9 × 10 -25 ), regardless of the phenotype., Conclusion: Our data demonstrate the value of ultradeep NGS for molecular diagnosis of PROS, highlight its substantial allelic heterogeneity, and confirm that optimal diagnosis requires fresh skin or surgical samples from affected regions. Our findings may be of value in guiding future recommendations for genetic testing in PROS and other mosaic conditions.Genet Med advance online publication 02 February 2017.

Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a rare autosomal dominant disorder whose main features are the abnormal shape, position and alignment of the eyelids. Type I refers to BPES with female infertility from premature ovarian failure while type II is limited to the ocular features. A causative gene, FOXL2, has been localized to 3q23. We report a black female who carried a de novo chromosomal translocation and 3.13 Mb deletion at 3q23, 1.2 Mb 5' to FOXL2. This suggests the presence of distant cis regulatory elements at the extended FOXL2 locus. In spite of 21 protein coding genes in the 3.13 Mb deleted segment, the patient had no other malformation and a strictly normal psychomotor development at age 2.5 years. Our observation confirms panethnicity of BPES and adds to the knowledge of the complex cis regulation of human FOXL2 gene expression., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Metanephric stromal tumor is a rare benign entity belonging to the group of metanephric renal tumors in children. Although metanephric stromal tumors can be cured by simple nephrectomy, differential diagnosis based on histopathologic criteria with other pediatric renal tumors requiring aggressive chemotherapy can be difficult. To our knowledge, cytogenetic characterization of metanephric stromal tumor has never been reported. We describe conventional ("R-bands" karyotyping) and molecular [fluorescence in situ hybridization (FISH), multicolor FISH, oligo array-comparative genomic hybridization] cytogenetic examinations of a metanephric stromal tumor in a 3-year-old boy. Cytogenetic analysis revealed a complex homogeneous gain between bands 17q22 and 17q25.3, resulting in partial triplication of the segment between bands 17q22 and 17q24.3, and duplication of the segment between bands 17q24.3 and 17q25.3. Cytogenetic confirmatory studies in metanephric stromal tumors are currently needed to assess 17q22q25.3 gain as a recurring cytogenetic abnormality of metanephric stromal tumors., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We report an unusual chromosome 22q11 deletion associated with an apparent complementary ring chromosome in a phenotypically normal woman with a family medical history of 22q11 deletion. Using peripheral blood samples, conventional karyotyping, Fluorescence In Situ Hybridization (FISH) analysis on metaphase spreads and oligo array-based comparative genomic hybridization (oligo array-CGH) were performed. After conventional cytogenetic examination, the chromosome formula was as follows: 47,XX,+r(?)[16]/46,XX[6]. The FISH analysis revealed that this patient had a rearranged chromosome 22 with decreased centromeric fluorescence intensity and deletion of the 22q11.2 locus. She also had a supernumerary ring chromosome composed of an alpha-satellite centromere of 22 origin and 22q11.2 locus. The oligo array-CGH profile showed a deletion of approximately 4.18 Mb on chromosome 22 with a log 2 intensity ratio mean deviation of the deleted region of about -0.29. The 22q11 deletion associated with a complementary ring chromosome described in our patient could be consistent with a centromere misdivision mechanism, with one chromosomal break occurring in the alpha-satellite array and a second one in the 22q11 locus, a mechanism which has recently been referred to as the McClintock mechanism., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)