Luis Daniel Campos-Acevedo

Background: Genetic eye diseases (GEDs) comprise a heterogeneous group of hereditary and de novo disorders that involve all ocular structures, including the retina, optic nerve, vitreous, anterior segment, and ocular development. Their marked clinical and genetic heterogeneity frequently delays diagnosis and access to genetic counseling, multidisciplinary management, and emerging gene-based therapies. Although ophthalmic deep phenotyping remains essential, we propose an approach that prioritizes genetic analysis, particularly in under-resourced healthcare settings with limited access to advanced imaging and electrophysiological tests. Methods: We conducted a retrospective observational study of 101 consecutive patients with suspected genetic eye diseases. All were evaluated at a tertiary referral center in northeastern Mexico between January 2020 and August 2023 through comprehensive ophthalmologic examination supplemented by optical coherence tomography, visual-field testing, and fundus photography when clinically indicated. All patients were offered early molecular testing while awaiting future tests, such as electrophysiological testing or further referral visits. Molecular testing consisted of an ophthalmology-focused next-generation sequencing multigene panel. Results: The primary outcome was molecular diagnostic yield. A clinically actionable molecular diagnosis was established in 45 patients, corresponding to an overall molecular diagnostic yield of 44.6%. A total of 165 variants were identified, including 70 pathogenic, 16 likely pathogenic, 43 variants of uncertain significance, and 36 likely benign variants. Usher syndrome was the most frequent molecular diagnosis (10/45, 22.2%), comprising nine patients with USH2A-associated Usher syndrome type 2 and one patient with MYO7A-associated Usher syndrome type 1B, followed by Stickler syndrome (8/45, 17.8%), oculocutaneous albinism (3/45, 6.7%), and Alström syndrome (2/45, 4.4%). Autosomal recessive disorders represented the predominant inheritance pattern (68.9%). Conclusions: Our findings support ophthalmology-focused multigene panels as an effective first-line diagnostic strategy for patients with suspected genetic eye diseases. Early molecular testing may shorten the diagnostic odyssey, optimize resource utilization, facilitate precision diagnosis and genetic counseling, and guide future targeted deep phenotypic evaluation, prognosis, and eligibility for emerging gene-specific therapies.

Background: The spinocerebellar ataxias (SCA) are a group of multiple inherited disorders. The molecular diagnosis of the specific type of SCA is challenging due to the diversity of hereditary patterns and genetic anomalies. Certain key clinical features can help shorten the differential diagnosis. Cases: At our center, we evaluated three patients presenting with gait disturbances. They were assessed by multiple hospital departments, and, due to suspected spinocerebellar ataxia, comprehensive genetic and ophthalmologic testing was performed, leading to diagnoses of SCA2, SCA7, and SCAR32. These cases highlight the importance of multidisciplinary evaluation for accurate diagnosis of complex neurogenetic disorders. All patients experienced prolonged diagnostic delays, requiring years of multiple consultations across different hospitals before reaching a definitive diagnosis. Literature Review: Among all published reports of patients with SCA, we consider that five distinct key clinical features can categorize many patients suffering from a possible SCA into different groups and reduce the potential differential diagnosis. Only two types of SCA presented macular anomalies, ten optic nerve involvements, one erythrokeratodermia, four hearing losses, and four dementias. Conclusions: Early referral to a multidisciplinary evaluation might help narrow the differential diagnosis of specific types of SCA, guiding the diagnostic work-up toward SCA1 and SCA7 in patients with macular involvement, or toward SCA1, SCA2, SCA3, SCA7, SCAR3, SCAR9, SCAR21, SCAR29, SCAR31, and SCAX3 in those with optic nerve involvement.

Beta ketothiolase deficiency is a hereditary metabolic disorder caused by the pathogenic variants of the ACAT gene, which encodes for the mitochondrial enzyme acetoacetyl-CoA thiolase. Patients with a deficiency of the enzyme experience recurrent episodes of metabolic ketoacidosis. Knowledge of the clinical course of this entity, together with the available diagnostic tests, allows for its early diagnosis and prompt intervention to avoid complications or death of the infant. In this study, we present a case of a 9-month-old girl that attended the emergency room and diagnosis was made at the first episode of metabolic ketoacidosis.

Traboulsi syndrome is a rare genetic disorder characterized by facial dysmorphism, lens subluxation, anterior segment anomalies, and spontaneous filtering blebs. The syndrome is due to mutations in the ASPH gene, which plays a crucial role in the development and maintenance of the lens. This case report describes the clinical and genetic findings in a Mexican male with Traboulsi syndrome, highlighting the identification of a novel ASPH variant. A 21-year-old male presented with trauma to the right eye while playing soccer. He had a history of lens subluxation and dysmorphic facial features. Ophthalmic examination revealed right eye lens subluxation into the anterior chamber (with signs of a previous episode of acute angle closure) and left eye posterior and inferior lens subluxation with sectorial iris atrophy. Genetic analysis identified a pathogenic ASPH variant (NM_004318.3:c.1892G>A, p.Trp631*) and a novel likely pathogenic variant (deletion of exons 20–21), confirming Traboulsi syndrome. This is the first instance of Traboulsi syndrome in the Mexican population. The absence of spontaneous filtering blebs in this patient supports previous reports of the wide phenotypic variability that could be related to the type of mutation. This novel ASPH variant expands the known genetic heterogeneity of Traboulsi syndrome.

Background: Wieacker-Wolff syndrome is an ultra-rare disease with X-linked inheritance characterized by arthrogryposis, intellectual disability, microcephaly, and distal limb muscle atrophy. Ophthalmic abnorm-alities such as ptosis, strabismus, and oculomotor apraxia have been reported in half of the patients. Wieacker-Wolff syndrome female-restricted (WRWFFR) is an even rarer disease recently used for females with a more severe phenotype.Materials and Methods: Clinical geneticist and ophthalmic examination, neuroimaging, and exome sequencing.Results: A 4 years-old girl with developmental and language delay, microcephaly, camptodactyly, digital pads, and arthrogryposis was identified by the clinical geneticist. Ophthalmic examination revealed deep-set eyes, high hyperopic astigmatism in both eyes, and reduced retinal nerve fiber layer thickness measured by optical coherence tomography. Exome sequencing identified a novel, probably pathogenic variant in the ZC4H2 gene NM_018684.3:c.145A>T p. (Lys49*) in heterozygosis.Discussion: WRWFFR is an ultra-rare disease with X-linked inheritance by variants in the ZC4H2 gene. This case reports a girl with a novel nonsense variant in the ZC4H2 gene and a severe phenotype; previous reports have identified WRWFFR in females with large deletions and nonsense mutations which could explain the manifestations in the current case report. A complete ophthalmic examination should be considered in patients with WRWFFR to detect the possibly associated optic nerve involvement and other previously described manifestations such as ptosis and strabismus.

Turner syndrome (TS) is caused by the total or partial loss of the second sex chromosome; it occurs in 1 every 2,500–3,000 live births. The clinical phenotype is highly variable and includes short stature and gonadal dysgenesis. In 1959, the chromosomal origin of the syndrome was recognized; patients had 45 chromosomes with a single X chromosome. TS presents numerical and structural abnormalities in the sex chromosomes, interestingly only 40% have a 45, X karyotype. The rest of the chromosomal abnormalities include mosaics, deletions of the short and long arms of the X chromosome, rings, and isochromosomes. Despite multiple studies to establish a relationship between the clinical characteristics and the different chromosomal variants in TS, a clear association cannot yet be established. Currently, different mechanisms involved in the phenotype have been explored. This review focuses to analyze the different chromosomal abnormalities and phenotypes in TS and discusses the possible mechanisms that lead to these abnormalities.

(1) Background: The interaction between single nucleotide variants (SNVs) associated with congenital heart diseases (CHDs) and their gene methylation status has not been well researched. The aim of the present study was to determine if there is a relationship between the methy lation status (MS) of genes and the allelic variants associated with CHDs. (2) Methods: Seven SNVs of the genes AXIN1, TBX1, TBX20, and MTHFR were selected from the literature. DNA extraction, genotyping, and a methylation analysis were performed on healthy subjects and subjects with CHDs. (3) Results: Twenty-two subjects with CHDs were selected as the case group (15 with ventricular septal defects (VSDs) and 7 with atrial septal defects (ASDs)), and 44 healthy subjects comprised the control group. The MTHFR and AXIN1 genes were hypermethylated in the control group when compared to the case group. When analyzed separately, those with atrial septum defects exhibited greater methylation, except for the gene MTHFR where there were no differences. Only the alternate alleles of MTHFR showed a significantly different methylation status in those without cardiopathy. (4) Conclusions: The MTHFR and AXIN genes were hypermethylated in the control group; however, only the alternate alleles of MTHFR (rs1801133 and rs1801131) showed a significantly different methylation status.

Emerging and re-emerging vector-borne infections are a global public health threat. In endemic regions, fever is the main reason for medical attention, and the etiological agent of such fever is not usually identified. In this study, non-specific febrile pathogens were molecularly characterized in serum samples from 253 patients suspected of arbovirus infection. The samples were collected in the southern border region of Mexico from April to June 2015, and February to March 2016. ZIKV, CHIKV, DENV, leptospirosis, and rickettsiosis were detected by qPCR and nested PCR to identify flavivirus and alphavirus genera. The results indicated that 71.93% of the samples were positive for CHIKV, 0.79% for ZIKV, and 0.39% for DENV, with the number positive for CHIKV increasing to 76.67% and those positive for ZIKV increasing to 15.41% under the nested PCR technique. Leptospira Kmetyi was identified for the first time in Mexico, with a prevalence of 3.16%. This is the first report of ZIKV in Mexico, as well the first detection of the virus in early 2015. In conclusion, the etiological agent of fever was determined in 94% of the analyzed samples.

Background: DNA methylation is the best epigenetic mechanism for explaining the interactions between nutrients and genes involved in intrauterine growth and development programming. A possible contributor of methylation abnormalities to congenital heart disease is the folate methylation regulatory pathway; however, the mechanisms and methylation patterns of VSD-associated genes are not fully understood. Objective: To determine if maternal dietary intake of folic acid (FA) is related to the methylation status (MS) of VSD-associated genes (AXIN1, MTHFR, TBX1, and TBX20). Methods: Prospective case–control study; 48 mothers and their children were evaluated. The mothers’ dietary variables were collected through a food frequency questionnaire focusing on FA and the consumption of supplements with FA. The MS of promoters of genes was determined in the children. Results: The intake of FA supplements was significantly higher in the control mothers. In terms of maternal folic acid consumption, significant differences were found in the first trimester of pregnancy. Significant differences were observed in the MS of MTHFR and AXIN1 genes in VSD and control children. A correlation between maternal FA supplementation and MS of AXIN1 and TBX20 genes was found in control and VSD children, respectively. Conclusions: A lower MS of AXIN1 genes and a higher MS of TBX20 genes is associated with FA maternal supplementation.

Pathogenic variants (PVs) of BRCA genes entail a lifetime risk of developing breast cancer in 50–85% of carriers. Their prevalence in different populations has been previously reported. However, there is scarce information regarding the most common PVs of these genes in Latin-Americans. This study identified BRCA1 and BRCA2 PV frequency in a high-risk female population from Northeastern Mexico and determined the association of these mutations with the patients’ clinical and pathological characteristics. Women were divided into three groups: aged ≤ 40 years at diagnosis and/or risk factors for hereditary breast cancer (n = 101), aged > 50 years with sporadic breast cancer (n = 22), and healthy women (n = 72). Their DNA was obtained from peripheral blood samples and the variants were examined by next-generation sequencing with Ion AmpliSeq BRCA1 and BRCA2 Panel using next-generation sequencing. PVs were detected in 13.8% group 1 patients (BRCA1, 12 patients; BRCA2, 2 patients). Only two patients in group 2 and none in group 3 exhibited BRCA1 PVs. Variants of uncertain significance were reported in 15.8% patients (n = 16). In group 1, patients with the triple-negative subtype, PV frequency was 40% (12/30). Breast cancer prevalence in young women examined in this study was higher than that reported by the National Cancer Institute Surveillance, Epidemiology (15.5% vs. 5.5%, respectively). The detected BRCA1 and BRCA2 PV frequency was similar to that reported in other populations. Our results indicate that clinical data should be evaluated before genetic testing and highly recommend genetic testing in patients with the triple-negative subtype and other clinical aspects.