Expanding the Molecular Spectrum of ANKRD11 Gene Defects in 33 Patients with a Clinical Presentation of KBG Syndrome.

KBG syndrome (KBGS) is a neurodevelopmental disorder caused by the Ankyrin Repeat Domain 11 (ANKRD11) haploinsufficiency. Here, we report the molecular investigations performed on a cohort of 33 individuals with KBGS clinical suspicion. By using a multi-testing genomic approach, including gene sequencing, Chromosome Microarray Analysis (CMA), and RT-qPCR gene expression assay, we searched for pathogenic alterations in ANKRD11. A molecular diagnosis was obtained in 22 out of 33 patients (67%). ANKRD11 sequencing disclosed pathogenic or likely pathogenic variants in 18 out of 33 patients. CMA identified one full and one terminal ANKRD11 pathogenic deletions, and one partial duplication and one intronic microdeletion, with both possibly being pathogenic. The pathogenic effect was established by RT-qPCR, which confirmed ANKRD11 haploinsufficiency only for the three deletions. Moreover, RT-qPCR applied to six molecularly unsolved KBGS patients identified gene downregulation in a clinically typical patient with previous negative tests, and further molecular investigations revealed a cryptic deletion involving the gene promoter. In conclusion, ANKRD11 pathogenic variants could also involve the regulatory regions of the gene. Moreover, the application of a multi-test approach along with the innovative use of RT-qPCR improved the diagnostic yield in KBGS suspected patients.

Clinical follow-up of young adults affected by Williams syndrome: experience of 45 Italian patients.

Williams-Beuren syndrome (WBS) is a multisystem disorder that requires ongoing management by a primary care physician familiar with the natural history and specific medical problems associated with the condition. While the natural history of the disease during infancy is well known, data about the adult WBS population have been published only in the last few years, and show a wide range of medical, neurological, and psychiatric problems. We investigated 45 young adult WBS patients (mean age 23 years, range 17-39 years) using a well-coordinated team which included a cardiologist, a nephrologist, an ophthalmologist, an endocrinologist, a gastroenterologist, orthodontist, and orthopedist. Here we describe the clinical features and medical complications in this cohort of patients. Most patients demonstrated a high frequency of multiple organ systems complications, in particular, abnormal body habitus; cardiovascular disease, and hypertension; sensorineural hearing loss; gastrointestinal symptoms including diverticular disease and abnormal glucose tolerance. We offer some suggestions for clinical monitoring which we propose will be useful in the overall care of adults with WBS.

Acro-dermato-ungual-lacrimal-tooth-like syndrome: report of a family with variable expression.

We report the case of a young boy with fine hair, mild nail dysplasia, blocked nasolacrimal ducts, absence of central incisors, bilateral oligodactyly of feet and anal stenosis. His father showed the same spectrum of anomalies with mild expression. He had mild nail dysplasia, blocked nasolacrimal ducts, inferior dental cysts with consequent premature tooth loss, frequent dental decays consequent to enamel abnormality and cutaneous syndactyly of the second and third right toe. The acro-dermato-ungual-lacrimal-tooth syndrome was suspected and molecular analysis of the P63 gene was performed, but no mutation was found. Although P63 gene analysis was negative, we think that both cases show clinical overlap with the acro-dermato-ungual-lacrimal-tooth syndrome and confirm the wide expression of this condition, even in the same family.