The link between hidradenitis suppurativa and phylloid hypomelanosis in partial trisomy-13 mosaicism: New evidences and further genetic/pathogenetic insights.

Partial trisomy-13 mosaicism (PT13M) is a rare condition. Among its possible associated cutaneous features, phylloid hypomelanosis (PH), characterized by leaf-like macules reminiscent of floral ornaments in the form of round or oval spots and patches and oblong lesions, is typical. Two cases of PH associated with hidradenitis suppurativa (HS) have been already reported in the literature. We report a third child with PH due to PT13M associated with HS-like lesions limited to hypomelanotic regions. We hypothesize that follicular occlusion genes may be located in the duplicated part of chromosome 13.

Novel case of paternal paracentric inversion causing partial trisomy 13 and review of the literature.

Partial trisomies have often been reported secondary to inversion mutations. These occurrences are most frequently associated with pericentric inversions. In this report, we describe the first documented case of partial trisomy 13 secondary to a parental paracentric inversion, in this case a paternal paracentric 13q inversion. Our Patient exhibits a variety of clinical findings including global developmental delay with intellectual disability, sensorineural hearing loss, bilateral congenital polar cataracts with associated foveal and optic nerve hypoplasia, right retinal detachment, atrial septal defect, absence of corpus callosum, celiac disease, microcephaly, as well as other dysmorphic features.

First report on chromosomal abnormalities in Eastern Morocco: Identification of a new case of a de novo partial trisomy 13q using single-nucleotide polymorphism array.

BACKGROUND: Chromosomal abnormalities are the main cause of birth defects, intellectual disability, and miscarriages. They contribute to significant human morbidity and infant mortality. Here we report for the first time the chromosomal abnormalities encountered in the population of Eastern Morocco. Furthermore, we describe a new case of a de novo partial trisomy 13q combined with a terminal deletion in an 11-day-old girl. METHODS: From November 2015 to March 2022, 195 patients from the BRO Biobank who were clinically suspected of having chromosomal abnormalities were referred to the cytogenetics laboratory of the Genetics Unit of the Faculty of Medicine and Pharmacy of Oujda for cytogenetic study. Karyotyping analysis was performed on peripheral blood samples using standard R banding techniques. To identify single-nucleotide polymorphism (SNP) and copy number variants (CNVs), Illumina SNP array was used. RESULTS: Among 195 studied cases, 32 (16.4 %) had abnormal karyotypes, of which 12 cases had numerical aberrations while 20 cases had structural aberrations. The most common numerical aberrations were Turner syndrome and Down syndrome followed by Edward, Patau, and Klinefelter syndromes. For structural aberrations, translocations were the most common, followed by derivative chromosomes, inversions, deletions, and an addition on chromosome 13 identified in an 11-day-old girl. To further characterize this addition, SNP array was carried out and revealed a 58.8-Mb duplication in region 13q14.3q34 associated with a 1-Mb deletion in region 13q34. Follow-up parental chromosomes analysis showed normal karyotypes for the parents, confirming that this partial trisomy 13q was de novo. Comparison of the phenotype associated with this novel duplication on chromosome 13q with those previously reported confirmed the considerable variability in the phenotype of the patients with partial trisomy 13q. CONCLUSION: This study provided the first report on chromosomal abnormalities in Eastern Morocco and it enriched the phenotype spectrum of partial trisomy 13q and further confirmed the genotype-phenotype correlations. Furthermore, these findings justify the need to set up microarray comparative genomic hybridization techniques in Morocco for better genetic diagnosis.

Moyamoya syndrome secondary to mitochondrial disease in a patient with partial trisomy 13q14 and 13q31: A novel case report and literature review.

Moyamoya syndrome (MMS) is a cerebrovascular disease characterized by stenosis of the internal carotid arteries and the formation of an abnormal vascular network at the base of the brain. MMS usually occurs secondary to various conditions, particularly Down syndrome, and sickle cell anemia, and presents with motor deficits, sensory symptoms, recurrent ischemic strokes, hemodynamic transient ischemic attacks, recurrent seizures, and hemorrhage. Trisomy 13 (Patau Syndrome) is a chromosomal abnormality that may be characterized by full or partial trisomy of chromosome 13. Phenotypic features of partial trisomy 13 include leukoencephalopathy, hippocampal hypoplasia, intellectual disability, facial anomalies, and others. Herein, we report a case of a 19-year-old female diagnosed with partial trisomy 13q, characterized by two large duplications in the 13q14 and 13q31 regions, with trisomy-induced bilateral MMS - the first known case to be discussed in literature. Particularly, our patient was identified to have a gain of 22Mb within the 13q14.11q21.31 region - a duplication that has not been described previously. Our patient suffered four strokes between the ages of 5 and 7, later developing intractable seizures, hemiplegia, spasticity in all limbs, global delay, and regression. Despite bilateral encephaloduroarteriosynangiosis and being on several antiepileptic medications, the MMS continued to progress, confounded by the partial trisomy 13. Studies must elucidate the association between mitochondrial damage and MMS, as well as mechanisms of epilepsy associated with chromosomal abnormalities, particularly in the context of underlying mitochondrial diseases.

Identification of partial trisomy 13q in two unrelated patients using single-nucleotide polymorphism array and literature overview.

BACKGROUND: Partial trisomy 13q is a less common chromosomal abnormality with a great clinical variability, among them, isolated partial trisomy 13q is extremely rare. Here, we report two new unrelated cases of partial trisomy 13q in Chinese families aiming to emphasize the genotype-phenotype correlation in partial trisomy 13q. METHODS: Enrolled in this study were two unrelated cases of partial 13q trisomy from two families in Quanzhou region South China. Karyotpe and single-nucleotide polymorphism (SNP) array analysis were employed to identify chromosome abnormalities and copy number variants in the families. RESULTS: A 72.9-Mb duplication in 13q14.11q34 region was identified using SNP array analysis in Patient 1 with an intellectual disability, developmental delay, seizures, gastric perforation, and other congenital malformations from a family with paternal inv(13)(p12q14.1). SNP array detection in Patient 2 revealed a 92.4-Mb duplication in 13q12.11q34 region combined with an 8.4-Mb deletion in Xq27.3q28 region with intellectual disability, developmental delay, cleft palate, and duplication of the cervix and the vagina. No chromosomal abnormality was elicited from the parents of Patient 2. CONCLUSIONS: In this study, we presented two new unrelated cases of partial trisomy 13q with variable features in Chinese population, which may enrich the spectrum of the phenotypes partial trisomy 13q and further confirm the genotype-phenotype correlation.

Keratoconus in a child with partial trisomy 13.

Background: Clinical studies suggest the importance of genetic components in the etiology of keratoconus. However, the contributing genes and variants remain elusive. We present a case of bilateral keratoconus in a child with partial trisomy 13, with a trisomic region spanning loci that have been associated with keratoconus.Materials and Methods: This is a single, retrospective case report of a child with a molecular diagnosis of partial trisomy 13, who was diagnosed with bilateral keratoconus for which at the age of 11 years, she underwent successive epithelium-off corneal cross-linking (CXL) procedures in both eyes, followed by temporary central tarsorrhaphy under general anesthesia.Results: Patient's molecular diagnosis was 70 Megabase trisomic region 13q14.11q34. Pre CXL pachymetry was 426 µm and 496 µm, maximum K values were 52.28 D and 55.45 D in right and left eyes, respectively; at last follow up (12 months post-op) these were 494 µm and 509 µm for pachymetry and maximum K values 50.50 D and 52.43 D in the right and left eyes, respectively. No signs of progression were detected.Conclusion: To the best of our knowledge, this is the first case report to document bilateral keratoconus in a child with partial trisomy 13, in whom successful epithelium-off CXL was achieved with general anesthesia. We emphasize the importance of screening, early diagnosis, and therapy of this treatable but rare cause of decreased vision in partial trisomy 13 patients.

De Novo Partial 13q22-q34 Trisomy with Typical Neurological and Immunological Findings: A Case Report with New Genetic Insights.

The partial trisomy 13q encompasses an extensive variability of phenotypic and radiological findings including leukoencephalopathy and brain malformations such as holoprosencephaly, callosal dysgenesis, hippocampal hypoplasia, olfactory hypoplasia, and vermian hypoplasia. We report for the first time a case of a 23-year-old patient affected by de novo partial 13q22.1q34 trisomy (41.7 Mb, 72,365,975-114,077,122x3) presenting with hemiparesis related to both ischemic and haemorrhagic cerebral lesions compatible with cerebral vasculitis due to a possible combination of genetic and immunological interaction.