13q deletion syndrome resulting from balanced chromosomal rearrangement in father: the significance of parental karyotyping

Gonadal Function in Boys with Bilateral Undescended Testes

Background

Bilateral undescended testes (BUDT) may be a marker of an underlying condition that affects sex development or maturation.

Aims

To describe the extent of gonadal dysfunction in cases of BUDT who had systematic endocrine and genetic evaluation at a single tertiary pediatric center.

Methods

A retrospective review was conducted of all boys with BUDT who had endocrine evaluation between 2008 and 2021 at the Royal Hospital for Children, Glasgow (RHCG). Continuous variables were analyzed using Mann-Whitney U and non-continuous variables using Fisher's exact, via Graphpad Prism v 8.0. Multivariable logistic regression was used to identify any associations between groups. A P < .05 was considered statistically significant.

Results

A total of 243 bilateral orchidopexies were performed at RHCG between 2008 and 2021. Of these 130 (53%) boys were seen by the endocrine team. The median (range) age at first orchidopexy was 1 year (0.2, 18.0) with 16 (12%) requiring re-do orchidopexy. The median External Masculinization Score of the group was 10 (2, 11) with 33 (25%) having additional genital features. Of the 130 boys, 71 (55%) had extragenital anomalies. Of the 70 who were tested, a genetic abnormality was detected in 38 (54%), most commonly a chromosomal variant in 16 (40%). Of the 100 who were tested, endocrine dysfunction was identified in 38 (38%).

Conclusion

Genetic findings and evidence of gonadal dysfunction are common in boys who are investigated secondary to presentation with BUDT. Endocrine and genetic evaluation should be part of routine clinical management of all cases of BUDT.

Signaling pathways driving ocular malignancies and their targeting by bioactive phytochemicals

Ocular cancers represent a rare pathology. The American Cancer Society estimates that 3,360 cases of ocular cancer occur annually in the United States. The major types of cancers of the eye include ocular melanoma (also known as uveal melanoma), ocular lymphoma, retinoblastoma, and squamous cell carcinoma. While uveal melanoma is one of the primary intraocular cancers with the highest occurrence in adults, retinoblastoma remains the most common primary intraocular cancer in children, and squamous cell carcinoma presents as the most common conjunctival cancer. The pathophysiology of these diseases involves specific cell signaling pathways. Oncogene mutations, tumor suppressor mutations, chromosome deletions/translocations and altered proteins are all described as causal events in developing ocular cancer. Without proper identification and treatment of these cancers, vision loss, cancer spread, and even death can occur. The current treatments for these cancers involve enucleation, radiation, excision, laser treatment, cryotherapy, immunotherapy, and chemotherapy. These treatments present a significant burden to the patient that includes a possible loss of vision and a myriad of side effects. Therefore, alternatives to traditional therapy are urgently needed. Intercepting the signaling pathways for these cancers with the use of naturally occurring phytochemicals could be a way to relieve both cancer burden and perhaps even prevent cancer occurrence. This research aims to present a comprehensive review of the signaling pathways involved in various ocular cancers, discuss current therapeutic options, and examine the potential of bioactive phytocompounds in the prevention and targeted treatment of ocular neoplasms. The current limitations, challenges, pitfalls, and future research directions are also discussed.

Multiplex ligation-dependent probe amplification versus fluorescent in situ hybridization for screening RB1 copy number variations in Egyptian patients with retinoblastoma

BACKGROUND

Retinoblastoma (RB) is the most common primary intraocular malignant tumor in children. RB is mostly caused by biallelic mutations in RB1 and occurs in hereditary and non-hereditary forms according to the "two-hit" theory. RB1 mutations comprise point mutations, indels, large deletions, and duplications. Genetic testing is essential for the comprehensive treatment and management of patients with RB.

AIM

The aim was to evaluate RB1 copy number variations (CNVs) using MLPA versus FISH assays in group of Egyptian patients with RB.

RESULTS

16.67% showed an RB1 deletion, abnormal methylation status, or both.

CONCLUSION

Our results suggested MLPA is a fast, reliable, and powerful method and should be used as a first-line screening tool for detecting RB1 CNVs in patients with RB. Moreover, MLPA is advantageous as it evaluates the methylation status/inactivation of RB1, not possible by FISH.

Complex translocation leading to13q interstitial deletion in a Moroccan child with retinoblastoma and intellectual disability

BACKGROUND

Retinoblastoma (RB) is the most common malignant intraocular tumor in children; it affects their eyes often even prenatally. RB may be sporadic or familial, due to germinal mutation in RB1 gene or by abnormal chromosomal abnormalities involving RB1 gene, located in 13q14. Monosomy of subband 13q14 as a partial deletion can also be responsible for RB with additional symptoms. The latter may be RB associated with psychomotor retardation, macrocephaly, broad forehead, thick earlobes, and bulbous nose.

MATERIALS AND METHODS

We present here the case of a boy from a consanguineous marriage with bilateral retinoblastoma, intellectual disability and facial dysmorphic features. Classical and molecular cytogenetics were used to recognize genotype-phenotype association.

RESULTS

The karyotype showed a three way translocation involving chromosomes 5, 12 and 13. Further molecular cytogenetics analysis revealed a deletion of 13q14 involving the tumor suppressor gene RB1.

CONCLUSION

This case highlights the impact of classical and molecular cytogenetics in diagnosis of rare genetic syndromes and for the genetic counselling of patients and their families. Pure molecular karyotyping analyses would miss the underlying chromosomal mechanism leading to the rearrangement.