Association Analysis Between the Functional Single Nucleotide Variants in miR-146a, miR-196a-2, miR-499a, and miR-612 With Acute Lymphoblastic Leukemia

Background

Acute lymphoblastic leukemia (ALL) is characterized by an abnormal proliferation of immature lymphocytes, in whose development involves both environmental and genetic factors. It is well known that single nucleotide polymorphisms (SNPs) in coding and noncoding genes contribute to the susceptibility to ALL. This study aims to determine whether SNPs in miR-146a, miR-196a-2, miR-499a, and miR-612 genes are associated with the risk to ALL in pediatric Mexican population.

Methods

A multicenter case-control study was carried out including patients with de novo diagnosis of ALL and healthy subjects as control group. The DNA samples were obtained from saliva and peripheral blood, and the genotyping of rs2910164, rs12803915, rs11614913, and rs3746444 was performed using the 5′exonuclease technique. Gene-gene interaction was evaluated by the multifactor dimensionality reduction (MDR) software.

Results

miR-499a rs3746444 showed significant differences among cases and controls. The rs3746444G allele was found as a risk factor to ALL (OR, 1.6 [95% CI, 1.05–2.5]; p = 0.028). The homozygous GG genotype of rs3746444 confers higher risk to ALL than the AA genotype (OR, 5.3 [95% CI, 1.23–23.4]; p = 0.01). Moreover, GG genotype highly increases the risk to ALL in male group (OR, 17.6 [95% CI, 1.04–298.9]; p = 0.00393). In addition, an association in a gender-dependent manner among SNPs located in miR-146a and miR-196a-2 genes and ALL susceptibility was found.

Conclusion

Our findings suggest that SNP located in miR-499a, miR-146a, and miR-196a-2 genes confer risk to ALL in Mexican children. Experimental analysis to decipher the role of these SNPs in human hematopoiesis could improve our understanding of the molecular mechanism underlying the development of ALL.

[Tumors that cause bone metastases]

INTRODUCTION

A metastasis is the tumor cell capacity to migrate from the primary tumor and implant itself in tissues of an organ at a distance by hematogenous, lymphatic or contiguity. The main causes of bone metastases are: breast, prostate and lung cancer. It usually occurs in patients over 50 years of age. There is a predilection for metastasizing to the axial skeleton.

OBJECTIVE

To determine the frequency of tumors that produce bone metastases in our institution.

MATERIAL AND METHODS

Observational, cross-sectional, descriptive study, for retrospective analysis of the cases of patients diagnosed with bone metastases.

RESULTS

193 cases; 121 women and 72 men with an age range of 42 to 84 years. Cancers associated with bone metastases were breast, lung, prostate, cervical and renal cancers; to a lesser extent other such as colon, thyroid, liver and skin. The most affected bones were axial skeleton: lumbar and dorsal spine, and in appendicular skeleton the femur in the diaphysiary region and in the humerus the proximal third. At present it has not been possible to improve the effectiveness of timely detection strategies, so bone pain should begin with a protocol of tumor suspicion.

CONCLUSIONS

More than 80% of the patients came for fracture. All patients had a history of pain greater than 12 months with no prior study protocol.

[Complex multiligament knee injury associated with patellar tendon rupture]

INTRODUCTION

Multi-ligament injury of the knee joint is defined as damage to two or more major ligaments. They are uncommon, with an incidence of ? 10:10,000. They constitute less than 0.02% of all orthopedic lesions. It is even less frequent to find an association of these with a complete rupture of the patellar tendon which presents with a prevalence of 2.4%.

CASE REPORT

22 year old male; he presented a high-speed accident with a diagnosis of multi-ligament left knee injury stage V of Schenck associated with complete patellar tendon rupture treated in a single surgical time with ligament reconstruction, four weeks after traumatic event. A score of 88.5 was obtained after eight months with the IKDC 2000 form for the subjective functional evaluation of the knee.

DISCUSSION

The definitive surgical treatment is performed four weeks after the injury. This reduces the risk of instability. In our clinical case, the patient is integrated into the activities of his daily life after eight months. To validate this technique as effective or good for its use, a greater number of patients treated in the same way is required. It is, however, suggested to contemplate as a management option.

CONCLUSION

These types of lesions are infrequent with a prognosis reserved.

Genotype-Environment Interaction Analysis of NQO1, CYP2E1, and NAT2 Polymorphisms and the Risk of Childhood Acute Lymphoblastic Leukemia: A Report From the Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia

Background: Acute lymphoblastic leukemia (ALL) is the main type of cancer in children. In Mexico and other Hispanic populations, the incidence of this neoplasm is one of the highest reported worldwide. Functional polymorphisms of various enzymes involved in the metabolism of xenobiotics have been associated with an increased risk of developing ALL, and the risk is different by ethnicity. The aims of the present study were to identify whether NQO1, CYP2E1, and NAT2 polymorphisms or some genotype-environmental interactions were associated with ALL risk in Mexican children.

Methods: We conducted a case-control study including 478 pediatric patients diagnosed with ALL and 284 controls (children without leukemia). Ancestry composition of a subset of cases and controls was assessed using 32 ancestry informative markers. Genetic-environmental interactions for the exposure to hydrocarbons were assessed by logistic regression analysis.

Results: The polymorphisms rs1801280 (OR 1.54, 95% CI 1.21–1.93), rs1799929 (OR 1.96, 95% CI 1.55–2.49), and rs1208 (OR 1.44, 95% CI 1.14–1.81) were found to increase the risk of ALL; being the risks higher under a recessive model (OR 2.20, 95% CI 1.30–1.71, OR 3.87, 95% CI 2.20–6.80, and OR 2.26, 95% CI 1.32–3.87, respectively). Gene-environment interaction analysis showed that NAT2 rs1799929 TT genotype confers high risk to ALL under exposure to fertilizers, insecticides, hydrocarbon derivatives, and parental tobacco smoking. No associations among NQO1, CYP2E1, and ALL were observed.

Conclusion: Our study provides evidence for the association between NAT2 polymorphisms/gene-environment interactions, and the risk of childhood ALL in Mexican children.

[Complications of supracondylar humeral fractures in children]

INTRODUCTION

Supracondylar fractures represent the most frequent cause of pediatric elbow injuries, at 64%, in children under eight years old. These fractures can present complications such as: A) Complications prior to treatment: 1) neurological, 2) vascular and 3) compartment syndrome. B) Complications after treatment: 1) early, in the first days after treatment: loss of reduction, neurological, vascular, compartment syndrome, infection of Kirschner wires. 2) Late complications in treatment: Angular deformity, loss of mobility, ossifying myositis, avascular necrosis of the trochlea, others.

OBJECTIVE

To determine the frequency of complications in humeral supracondylar fractures in less than eight years.

MATERIAL AND METHODS

A retrospective, observational cohort study was conducted in patients under 8 years of age during the period of March 2014 to February 2018.

RESULTS

277 patients were obtained with the following percentages: cubitus varus 3.97%, neurological lesions prior to surgical treatment 1.44%, early neurological complications to treatment 1.44%, infections of Kirschner needles 0.72%, cubitus valgus 0.72%, loss of mobility 0.36%.

CONCLUSIONS

The most common complication of humerus supracondylar fractures in this study was cubitus varus and neurological complications prior to treatment.

[Benign tumors that cause fractures in children]

INTRODUCTION

A pathological fracture is defined as that which occurs through an abnormal bone. Approximately 20,000 benign neoplasms of the musculoskeletal system are diagnosed each year. Often the pain of the fracture is the first symptom of a pathological process in the bone. The site, age and radiographic appearance create a differential diagnosis for pathological fractures that remains broad. The clinical examination evaluates the condition of the skin, palpating any tissue mass and determining if there are local inflammatory signs such as erythema, heat or edema. The biopsy is highly recommended to confirm the diagnosis of a pathological fracture.

OBJECTIVE

To determine which benign bone tumors and pseudotumoral lesions produce fractures in childrens bones more frequently in our institution.

MATERIAL AND METHODS

Cross-sectional retrospective study, review of records of patients with diagnosis of pathological fracture, attended in the period from March 2013 to March 2017, were reviewed. Results: The benign tumors that caused fractures in previously damaged areas were: aneurysmal bone cyst 13, enchondroma 5, osteoid osteoma 3, giant cell tumor 2.

CONCLUSION

At our institution, aneurysmal bone cysts were the benign tumors that most frequently produce pathological fractures in children, with predominance in males.

[Osteochondromas: introducing the subungual osteochondroma]

INTRODUCTION

Subungual osteochondromas are benign tumors of the sub- or periungual region, causing lifting, ulceration and deformity at that level.

OBJECTIVE

To research the incidence of subungual osteochondromas in a specific pediatric population.

MATERIAL AND METHODS

Retrospective, transversal, descriptive and observational study based on the review of records with a histopathological result of osteochondroma from 2001 to 2014.

RESULTS

The pathological assessment featured four osteochondromas that corresponded to the subungual presentation, with an equal gender distribution of 1:1, an average age of 9.5 years, right: left ratio of 3:1; the 4th finger was the most affected.

DISCUSSION

Subungual osteochondroma has an incidence of 8.5% of all osteochondromas.

[Comparative study of the management of congenital brachymetatarsia with elongation with callotaxis]

Brachymetatarsia is the > 5 mm shortening of the metatarsal parabolic arc of the foot, in one or more metatarsals. It is directly related with the early closure of the epiphyseal cartilage or with early fusion of the epiphyseal line of the distal end of the metatarsal. The fourth metatarsal is usually the most affected one. Females are more commonly affected, with a female to male ratio of 25:1; 72% of cases have bilateral involvement. The causes may be congenital, posttraumatic or result from specific conditions. A prospective, comparative study was conducted of patients with a diagnosis of congenital brachymetatarsia seen in 2007-2008 and 2008-2012. Seven patients were included in the former period: six girls and one boy. Eight patients were included in the latter period: five girls and three boys. The mean shortening achieved in the first group was 21.1 mm; in the second one, 18 mm, without regression. The daily distraction in both groups was 0.5 mm. Metatarsal elongation by means of callotaxis with external fixators is an appropriate procedure for adolescent patients about to achieve epiphyseal closure. The best results are obtained with gradual distraction at a rate of 0.5 mm per day.

[Relative clavicle shortening in pediatric fractures: its importance when selecting conservative treatment]

BACKGROUND

Clavicle fractures represent 2-15% of pediatric fractures. The literature suggests operating on patients over 9 years of age with major shortening or severe comminution in the fracture line. However, no one establishes shortening or angulation parameters for conservative treatment in children. In pediatric patients it is important to take into account relative shortening, that is, the one caused by a fracture when compared with the length of the healthy clavicle.

OBJECTIVE

To know the effect of relative clavicle shortening on movement in pediatric fractures treated conservatively.

MATERIAL AND METHODS

Retrospective, longitudinal, observational study. We radiographically measured the relative shortening of the fractured clavicle comparing it with the healthy side at the time of the fracture and after fracture healing. Shortening was expressed in percentages. The following views were used: comparative anteroposterior view of the shoulders and panoramic view of both shoulders. Patients were divided into 2 groups: under 9 years and 9-15 years of age.

RESULTS

We analyzed 94 fractures; 31 in females and 63 in males. No pseudoarthrosis or symptomatic malunion occurred. The prognosis was good regardless of the initial shortening percentage. Age and shortening are proportionally related with the rehabilitation period and the restoration of painless ranges of motion. The value ranges recorded for shortening were 9.5 to 28%.

CONCLUSIONS

The surgical indications for shortening resulting from pediatric clavicle fractures should be revised. We have observed good results despite major shortening and total displacement.

[Infected pseudoarthrosis of the tibia, a pediatric case. Case report and literature review]

Chronic posttraumatic osteomyelitis and infected pseudoarthrosis of the tibia are complex problems associated with considerable morbidity which may compromise the viability of the involved limb. The most frequent age of presentation is 2 to 6 years, with predominance in males at a 2:1 ratio. We present the case of a male 4 year-old patient with diagnosis of infected pseudoarthrosis. During the physical exam a fistula was detected in the anterior aspect of the right leg, with discharge of purulent material, and inability for weight bearing and gait. X-rays, culture of the exudate and biopsy were performed. Treatment consisted of antimicrobial therapy, surgical debridement's, and application of an autologous bone graft. The infection was controlled, the tibia healed, and function was restored.

[Proximal focal femoral deficiency complicated by a proximal femur fracture]

Proximal focal femoral deficiency (PFFD) is a rare skeletal condition characterized by development failure of the subtrochanteric region of the femoral axis, with several degrees of shortening of the proximal region. There are no case reports of patients with this condition associated with a subtrochanteric fracture. We therefore describe herein the case of a newborn patient with clinical and radiographic diagnosis of proximal focal femoral deficiency complicated by a proximal femur fracture, and managed conservatively with pelvipodalic immobilization, which led to bone healing. The patient will continue to be managed in the long-term to assess and treat the sequelae of PFFD according to the growth stage he is in.

[Elongation with callotaxis for congenital brachymetatarsia]

OBJECTIVE

To present 10 cases of congenital brachymetatarsia treated with elongation by means of callotaxis with external minifixators.

INTRODUCTION

Brachymetatarsia of one or more of the matatarsals involving one or both extremities is a congenital condition, more frequent in the right foot, with the 4th metatarsal most commonly affected.

MATERIAL AND METHODS

From May 2007 to September 2008, 7 patients with congenital brachymetatarsia, ages 8 to 15 years, were operated on. Two metatarsals were involved in 3 of them and thus the series included 10 procedures. All of them underwent lengthening through callotaxis with a monoaxial external mini-fixator.

RESULTS

Mean lengthening was 21.1 mm, with a range of 17 to 25 mm. The complications included two cases of lengthening regression of 5 mm each. Delayed healing was reported in one of these two cases, and healing occurred spontaneously at 6 months. Nine metatarsals healed without any problems; no infections or material intolerance occurred.

CONCLUSION

Lengthening of metatarsals through callotaxis with external mini-fixators is an appropriate procedure for pediatric and adolescent patients with congenital brachymetatarsia.