Clinical and molecular analysis of 26 individuals with Noonan syndrome in a reference institution in Colombia.

Our aim was to characterize the phenotype and genotype of individuals with Noonan syndrome in Colombia. There are published cohorts of Noonan individuals from several countries in Latin America including Brazil, Chile, and Argentina, but none from Colombia. We described 26 individuals with NS from a single large referral center in the South West of Colombia using an established database in the genetics department and hospital records search using ICD-10 codes. All patients included in this study were evaluated by a medical geneticist and have molecular confirmation of NS diagnosis. The median age at referral was 3.5 years (range, 0-39), and at molecular diagnosis was 5 years (range, 0-40). Patients mostly originated from the southwest region of Colombia (19/26, 73%). Pathogenic variants in PTPN11 are the most common cause of NS in Colombian individuals followed by SHOC2 and SOS1 variants. The prevalence of cardiomyopathy was low in this population compared to other populations. Further research is needed with a larger sample size and including different regions of Colombia to correlate our findings. This study provides new information about time to diagnosis of NS in Colombia, genotypes, and provides important information to help develop guidelines for diagnosis and management of this disease in the region.

Case report: A novel COL3A1 variant in a Colombian patient with isolated cerebrovascular involvement in vascular Ehlers-Danlos syndrome.

Introduction: To date, approximately 600 unique pathogenic variants have been reported in COL3A1 associated with vascular Ehlers-Danlos syndrome (vEDS). The objective of this study was to describe a patient with a novel variant in COL3A1 associated with vEDS. Case report: We describe the clinical history and thorough phenotyping of a patient with brain aneurysms and identified a novel pathogenic variant in COL3A1. This male patient reported transient focal neurologic symptoms. Physical examination showed abnormal atrophic scarring, horizontal stretch marks under the arms, and an acrogeric appearance of the skin of the hands and feet. Brain imaging revealed extensive dilation of both internal carotids and the vertebrobasilar system. Molecular analysis identified a variant in COL3A1 (NM_000090.4):c.3058G>T p.(Gly1020Cys), which was classified as likely pathogenic. Currently, the patient has never had an event concerning dissection/rupture of tissues that could be affected in this condition. Conclusion: This report demonstrates that exhaustive evaluation with clinical and genetic approaches should be considered in patients with vascular abnormalities. vEDS has a variable clinical presentation and often goes unrecognized, even though it is related to life-threatening complications and a shortened life expectancy. Diagnosis confirmed by genetic testing is crucial to determining appropriate surveillance, prevention, treatment, and genetic counseling.

Reclassification of the HPGD p.Ala13Glu variant causing primary hypertrophic osteoarthropathy.

Here, we highlight the case of a 31-yr-old man who had clinical features of primary hypertrophic osteoarthropathy (PHOAR) and harbored a homozygous variant (c.38C > A, p.Ala13Glu) in the HPGD gene, as indicated by whole-exome sequencing (WES). This variant has been previously classified by our laboratory as a variant of uncertain significance (VUS). However, another patient with the same phenotype and the same homozygous variant in HPGD was subsequently reported. In reassessing the variant, the absence of this variant in the gnomAD population database, supporting computational predictions, observation in homozygosity in two probands, and specificity of the phenotype for HPGD, all provide sufficient evidence to reclassify the HPGD c.38C > A, p.Ala13Glu variant as likely pathogenic.

A Novel APOC2 Mutation in a Colombian Patient with Recurrent Hypertriglyceridemic Pancreatitis.

Hypertriglyceridemia is a common disease with only 2% of cases exhibiting monogenic mutations. Familial chylomicronemia syndrome (FCS) is a rare genetic condition associated with recurrent and severe episodes of pancreatitis and is mainly caused by mutations in the LPL gene, with few cases related to abnormal function of apolipoprotein C-II. This is a 50-year-old female with a past medical history of arterial hypertension, miscarriage and recurrent pancreatitis. In the last four years, her triglycerides and lipase concentration reached >3000 mg/dL and >700 U/L, respectively. The patient was not responsive to statins, fibrates, or tetrahydrolipstatin. A novel homozygous frameshift mutation on exon 3 of the APOC2 gene was detected, c.133_134delTC. Subsequent Sanger sequencing confirmed that three first-degree relatives were carriers of the same mutation. To the best of our knowledge, we are reporting the first Colombian patient with FCS due to an APOC2 mutation. We propose that this mutation caused recurrent hypertriglyceridemic pancreatitis.

The fifth female patient with Myhre syndrome: further delineation.

We report the fifth female patient with Myhre syndrome (MS) and review the literature. She is a 13-year-old Mexican girl whose phenotype fulfills all the clinical and radiological criteria reported in MS such as typical facies, short stature, limited joint mobility, and short hands and feet. The physical habitus of MS is described and a square body shape is clearly distinguished in all cases. As the typical muscular build is present mainly in male patients, the MS muscular appearance may be hormonally influenced.

First case reported of Turner syndrome and trisomy 14 chromosomal mosaicism in a patient.

A 25-year-old woman with a mosaic 45,X/47XX,+14 karyotype is reported. She presented with short stature, short downward slanting palpebral fissures, broad nasal bridge, mouth with downturned corners, short and wide neck, swirly hyperpigmentation of the skin, and body asymmetry secondary to right hemihyperplasia. As there was an admixture of 45,X and trisomy 14, it was not possible to determine the cell line that had the greatest influence on the phenotype. We postulate that the proposita's survival until the third decade was owing to the chromosomal complementation of both aneuploidy cell lines. To our knowledge, this chromosomal association has not been previously reported.