Background and aims Syndrome deletion of chromosome region 1 p36 is a chromosome syndrome with multiple anomalies, congenital heart disease and mental retardation. Frequency of this syndrome is 1 in 5000 births. Rare variant deletion p36 is deletion 1 p36.33-p36.32 include genes PRDM16 and LMNA genes. Mutations in these genes were described in patients with dilated cardiomyopathy and left ventricular noncompaction. Our aim was to determine the correlations between genotype and phenotype in patients with multiple anomalies, congenital heart disease and developmental delay, which carried different deletions in 1 p36 chromosome region.

Methods We used MLPA method for detection of deletions in 1 p36.33-p36.32 chromosomal region and CytoScan HD microarray solutions to determine the exact borders of the deletion Case No1: Girl, 7 years old. Cardiomyopathy identified in 2009. Clinical features: mild face hypoplasia, deep set eyes, long philtrum, prominent forehead, wide nasal tip, low-set ears, brachydactyly, wide terminal phalanges, noncompaction cardiomyopathy of dilated variant and abdominal aorta hypoplasia. Case No2: Girl, 2 years old. Heart disease was detected in first year of life. Clinical features: Prominent forehead, mildface hypoplasia, short palpebral fissure, epicanthal folds, high-arched palate, irregular teeth, duodenal atresia, left ventricular noncompaction, mental retardation.

Results We detected in 1 p36.33-p36.32 chromosomal region the 3797 kb deletion in the first case and 2263 kb deletion in the second case

Conclusions Detection deletion of chromosomal region 1 p36 in patients with heart disease, congenital anomalies, mental retardation and developmental delay is important for the correct diagnosis, treatment and prevention this disease in families. We offer diagnostic algorithm which combines MLPA as a screening method and CytoScan HD microarray technology as a more precise method.This algorithm allowed us to find phenotype correlations on the basis of the deleted regions.