1q21.1 deletion syndrome

The syndrome is a form of the 1q21.1 copy number variations, and it is a deletion in the distal area of the 1q21.1 part.

[3] Approximately 75% of all children with a 1q21.1 microdeletion exhibit delayed development, notably in motor skills such as sitting, standing, and walking.

[1] Individuals may have generalized mild learning difficulties; about 30% of those diagnosed with 1q21.1 deletion syndrome are affected.

[1][4] Genitourinary abnormalities include vesicoureteral reflux, hydronephrosis, inguinal hernia, cryptorchidism, and genital malformations.

[6][4][1] The majority of affected people have normal neurologic physical examinations, however hypotonia and tremors are quite common.

Researchers are attempting to determine which missing genes may contribute to 1q21.1 deletions' specific characteristics.

Because some people with a 1q21.1 microdeletion have no clear associated traits, it is hypothesized that additional genetic and environmental factors influence the development of symptoms.

Approximately 20 to 40 days after fertilization, something goes wrong in the construction of the body parts and brain, which leads to a chain reaction.

The copy number of sequences can be determined using chromosome microarrays or targeted deletion analysis by fluorescence in situ hybridization.

Because of the vast range of symptoms, ophthalmologic, cardiac, developmental, neurological, and psychiatric evaluations may be helpful in identifying the manifestations of 1q21.1 deletion.

Different developmental abnormalities of the skull and genitourinary system can be identified with brain imaging and renal ultrasounds.

However, these CNVs are incompletely penetrant, therefore it is likely that the actual prevalence in the general population is greater than the current predictions.

Further research confirmed that the odds on a relation between schizophrenia and deletions at 1q21.1, 3q29, 15q13.3, 22q11.21 en Neurexin 1 (NRXN1) and duplications at 16p11.2 are at 7.5% or higher.