Land use as an effective factor on the occurrence of chromosomal diseases in Brazil.

BACKGROUND: The occurrence of chromosomal diseases is a worldwide health problem. The use of agrochemicals, urbanization processes, and solar radiation can be predictive factors of the elevated risk of congenital malformations. In this sense, predicting the geographical potential of the distribution of chromosomal diseases has high relevance for public health. OBJECTIVES: This study aimed to describe chromosomal prevalence in Brazil regions, from 2005 to 2015, to model a potential distribution of chromosomal disease occurrence probability associated with land use. METHODS: We used chromosomal prevalence to model a potential distribution of chromosomal diseases using machine learning algorithms. As the predictors of the models, we used the variables global forest canopy height, distance from the built-up area, and solar radiation. We characterized the predictive areas as potential occurrence of chromosomal diseases by land use and occupation. RESULTS: Georeferenced data of 43,672 karyotypes detected 7,237 cases of chromosomal diseases and used 5,362 to build the models. The models generated were accurate (TSS>0.5). DISCUSSION: The areas with greater occurrence of chromosomal diseases present a significant association with pasture areas, crops and agroforestry systems, and urbanized areas. This research is the first Brazilian study with this approach that seems promising in predicting the potential distribution of chromosomal diseases. Therefore, it can be an excellent management tool in public health.

An Apparently Balanced Complex Chromosome Rearrangement Involving Seven Breaks and Four Chromosomes in a Healthy Female and Segregation/Recombination in Her Affected Son.

Duplication of the distal 1q and 4p segments are both characterized by the presence of intellectual disability/neurodevelopmental delay and dysmorphisms. Here, we describe a male with a complex chromosome rearrangement (CCR) presenting with overlapping clinical findings between these 2 syndromes. In order to better characterize this CCR, classical karyotyping, FISH, and chromosomal microarray analysis were performed on material from the patient and his parents, which revealed an unbalanced karyotype with duplications at 1q41q43 and 4p15.2p14 in the proband. The rearrangements, which were derived from a maternal balanced karyotype, included an insertion of a segment from the long to the short arm of chromosome 1, a balanced translocation involving chromosomes 14 and 18, and an insertion of a segment from the short arm of chromosome 4 into the derived chromosome 14. This study aimed to better define the clinical history and prognosis of a patient with this rare category of chromosomal aberration. Our results suggest that the frequency of CCR in the general population may be underestimated; when balanced, they may not have a phenotypic effect. Moreover, they emphasize the need for cytogenetic techniques complementary to chromosomal microarray for proper genetic counseling.