Late effects of medulloblastoma treatment: multidisciplinary approach of survivors

PURPOSE

Medulloblastoma is one of the brain tumors with increased life expectancy due to improvements in treatment approaches. Besides the promising results, various undesirable effects can be encountered. This study's aim is to review long-term follow-up outcomes of our cases with medulloblastoma.

METHODS

Age at diagnosis, histological type of medulloblastoma, resection extension, chemotherapy and radiotherapy schemes, follow-up duration, and endocrinological, neuropsychiatric, cardiological, auditory, and visual examination results were evaluated in 20 patients diagnosed between 2007 and 2018 and followed 5 years and more.

RESULTS

Twenty of 53 patients were included to the study. Eleven (55%) were male. Mean age at diagnosis was 6.95 years; mean age at the time of the study was 14 years. Mean follow-up time was 8.95 years. In terms of surgery, 14 (70%) were gross total, 1 (5%) was near total, and 2 (10%) were subtotal resection. In histopathological examination, 14 (70%) were classical medulloblastoma, 4 (20%) were desmoplastic medulloblastoma, and 1 (5%) was anaplastic medulloblastoma. With regard to endocrinological evaluation, 15 (75%) patients had hypothyroidism, 5 (25%) had growth hormone deficiency, 7 (35%) had clinical growth hormone deficiency, and 5 (25%) had sex hormone disorders. In neuropsychiatric examination, 11 (55%) patients had neurological sequelae, 18 (90%) patients had psychiatric issues, and 14 (70%) patients had two or more neuropsychiatric problems simultaneously. One (5%) patient had mitral valve insufficiency. Twelve patients (60%) had hearing loss. According to visual examination, 6 (30%) patients had refraction problem, 4 (20%) had cataract, and 1 (5%) had dry eye.

CONCLUSION

Careful monitoring of long-term side effects is important for improving the quality of life of medulloblastoma patients. Besides endocrinological and other somatic sequelae of the disease and treatment, increased neuropsychiatric problems showed us that only cure is not the issue while treating childhood medulloblastoma.

Assessment of biochemical bone markers of osteoporosis in children with thalassemia major

BACKGROUND

Beta thalassemia major (β-TM) is a common cause of skeletal morbidity and is associated with increased bone fracture risk, particularly in inadequately transfused children. The aim of this study was to investigate some potential biochemical markers as possible early predictors of BMD variations in children with β-TM.

METHODS

The study included 38 children with β-TM and 40 sex-age matched controls. All patients were subjected to BMD assessment by dual-energy X-ray absorptiometry (DEXA). Serum beta-crosslaps (beta-CTx), osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL), urinary deoxypyridinoline (DPD) and ferritin levels were compared between the groups.

RESULTS

Serum OPG levels were significantly lower in thalassemic children than in controls. The mean ratio of RANKL/OPG was significantly higher in the thalassemic patients than in the control group. Osteoporosis was detected in 10 (3 female and 7 male) of 38 patients (26.3%) according to the femur Z score and in 6 of them (4 male and 2 female) (15.8%) according to the spine Z score.

CONCLUSIONS

Serum OPG concentrations can be used as a biochemical marker in screening patients with beta-thalassemia major for the development of osteoporosis.

First pediatric case with primary familial brain calcification due to a novel variant on the MYORG gene and review of the literature

Variants in the myogenesis-regulating glycosidase (MYORG) gene which is known as the first autosomal recessive gene that has been associated with primary familial brain calcification (AR-PFBC). Although adult patients have been reported, no pediatric case has been reported until now. Herein, we review the clinical and radiological features of all AR- PFBC patients with biallelic variants in the MYORG gene who were reported until now, and we report the youngest patient who has a novel homozygous variant. Since the first identification of the MYORG gene in 2018, 74cases of MYORG variants related to AR-PFBC were evaluated. The ages of symptom onset of the patients ranged between 7.5 and 87 years. The most frequent clinical courses were speech impairment, movement disorder and cerebellar signs. All patients showed basal ganglia calcification usually bilaterally with different severities. Conclusion; herein, we reported the first pediatric patient in the literature who had a novel homozygous variant in the MYORG gene with mild clinic findings.

Novel Mutations in Obesity-related Genes in Turkish Children with Non-syndromic Early Onset Severe Obesity: A Multicentre Study

OBJECTIVE

Non syndromic monogenic obesity is a rare cause of early onset severe obesity in the childhood period. This form may not be distinguishable from other forms of severe obesity without genetic analysis, particularly if patients do not exibit any physical abnormalities or developmental delay. The aim of this study was to screen 41 different obesity-related genes in children with non-syndromic early onset severe obesity.

METHODS

Children with severe (body mass index-standard deviation score >3) and early onset (<7 years) obesity were screened by next-generation sequencing based, targeted DNA custom panel for 41 known-obesity-related genes and the results were confirmed by Sanger technique.

RESULTS

Six novel variants were identified in five candidate genes in seven out of 105 children with severe obesity; two in SIM1 (p.W306C and p.Q36X), one in POMC (p.Y160H), one in PCSK1 (p.W130G fs Ter8), two in MC4R (p.D126E) and one in LEPR (p.Q4H). Additionally, two previously known variations in MC4R were identified in four patients (p.R165W in three, and p.V166I in one).

CONCLUSION

We identified six novel and four previously described variants in six obesity-related genes in 11 out of 105 childrens with early onset severe obesity. The prevalence of monogenic obesity was 10.4% in our cohort.

The Effects of Electromagnetic Field on the Endocrine System in Children and Adolescents

Children are exposed to various kind of non-ionizan radiation in their daily life involuntarily. The potential sensitivity of developing organism to the effects of radiofrequency (RF) signals, the higher estimated specific absorption rate (SAR) values of children and greater lifetime cumulative risk raised the scientific interest for children's vulnerability to electromagnetic fields (EMFs). In modern societies, children are being exposed to EMFs in very early ages. There are many researches in scientific literature investigating the alterations of biological parameters in living organisms after EMFs. Although the international guidelines did not report definite, convincing data about the causality, there are unignorable amount of studies indicating the increased risk of cancer, hematologic effects and cognitive impairment. Although they are less in amount; growing number of studies reveal the impacts on metabolism and endocrine function. Reproductive system and growth look like the most challenging fields. However there are also some concerns on detrimental effects of EMFs on thyroid functions, adrenal hormones, glucose homeostasis and melatonin levels. It is not easy to conduct a study investigating the effects of EMFs on a fetus or child due to ethical issues. Hence, the studies are usually performed on virtual models or animals. Although the results are conflicting and cannot be totally matched with humans; there is growing evidence to distress us about the threats of EMF on children.

The Effects of Six-Month L-Thyroxine Treatment on Cognitive Functions and Event-Related Brain Potentials in Children with Subclinical Hypothyroidism

OBJECTIVE

The aim of this study was to investigate the cognitive status of children with subclinical hypothyroidism (SH) before and after L-thyroxine (L-T4) treatment using event-related potentials (ERPs) and neuropsychological tests.

METHODS

This prospective study was conducted on a series of 20 children with mild SH (free T4 normal and thyroid-stimulating hormone level within 5-10 µIU/L) who underwent clinical and cognitive assessment before L-T4 treatment and 6 months afterwards. The recordings of ERPs were done at the time of diagnosis and after 6 months of euthyroid state. Neuropsychiatric tests for attention, perception, close and remote memory were performed on all patients and on the control group which consisted of 20 healthy children of normal intelligence.

RESULTS

While pretreatment verbal memory (VM) and verbal recall (VR) scores of the SH group were significantly lower than those of the control group (p=0.004 and 0.012, respectively), no significant differences between the post-treatment and control groups were found in these scores after 6 months of L-T4 treatment. Post-treatment VM and VR scores were significantly higher than the pretreatment scores in the SH group (p=0.008 and p=0.0001). There were no significant differences between the pre-and post-treatment values of electrophysiological evaluation in N1, P2, P3 latencies or P3 amplitude (p>0.05), although there was a significant decrease in N2 latency in the post-treatment group (p=0.03).

CONCLUSION

SH affects cognition in children and L-T4 replacement therapy leads to normalization of cognitive functions. Neuropsychological tests can be used as complementary measures in the evaluation of children with SH. Determining the association between ERPs and SH would contribute to the comprehensive evaluation of these children.

Iodine, copper, zinc, selenium and molybdenum levels in children aged between 6 and 12 years in the rural area with iodine deficiency and in the city center without iodine deficiency in Hatay

AIM

Thyroid diseases related with iodine deficiency are observed commonly in our country and in the world. In this study, we aimed to investigate iodine deficiency in urine and selenium, zinc, copper or molybdenum deficiency which may accompany this in children aged between 6 and 12 years in two schools in the province of Hatay (endemic goitre region).

MATERIAL AND METHODS

This study is a case-control field-study in which students aged between 6 and 12 years were included. One hundred fourteen subjects from the village of Tanışma related to the center of our province and 100 subjects from the city center of Hatay (Antakya) were included in the study. Iodine, selenium, zinc, copper and molybdenum levels were measured in the urine samples of the students included in the study.

RESULTS

Iodine deficiency was found with a severe (5%), moderate (18.4%) and mild degree (43%), respectively in the village of Tanışma. Mild iodine deficiency (7%) was found in the center of Hatay. No moderate and severe iodine deficiency was found in the control group. A significant difference was found between the groups in terms of urine iodine excretion (p<0.001). A significant correlation was found between the levels of iodine, selenium, zinc and molybdenum (p<0.05). A moderately positive correlation was found between iodine and selenium (p<0.001). A moderately positive correlation was found between iodine and zinc levels (p<0.001) and a weak correlation was found between iodine and molybdenum (p<0.01). No significant correlation was found between iodine level and copper level (p>0.05).

CONCLUSIONS

Selenium and zinc deficiency may accompany iodine deficiency. Selenium and zinc deficiency should be considered in individuals who are found to have iodine deficiency especially in endemic goitre regions.

Primary hypogonadism in a case with XLAG syndrome

Patients with X-linked lissencephaly with ambiguous genitalia (XLAG) syndrome present with lissencephaly, agenesis of the corpus callosum, refractory epilepsy of neonatal onset, microcephaly, and male genotype with ambiguous genitalia. The basis of the ambiguous genitalia in XLAG syndrome is not well-known. We report a case of the fourth child of healthy consanguineous parents who was presented to the hospital because of non-febrile seizures at 2 months of life. On physical examination, microcephaly, some dysmorphic face features, and ambiguous genitalia were determined. The cranial magnetic resonance imaging of the patient showed lissencephaly, agenesis of the corpus callosum, and enlarged ventricles. His karyotype was 46, XY. He had undetectable testosterone levels and elevated gonadotropins. Neither testicular tissue nor any testosterone response to human chorionic gonadotropin stimulation test was observed. These findings suggest that the hypogonadism in this patient with XLAG syndrome is primary hypogonadism due to gonadal agenesis or dysgenesis.