Genotype-phenotype correlation was originally attempted by Miyake et al. [2004] and refined by Failla et al. [2008] based on a 4.5 Mb deleted segment shared by three affected individuals. These three individuals had in common psychomotor and growth retardation, disturbance in extraocular motility, palatal anomalies, downturned corners of the mouth, lowset ears, widely spaced nipples, small feet, and 5th finger clinodactyly. Here we report on a father and son who have a 1.17 Mb deletion of 12q12. Both individuals had growth retardation in infancy, mild dysmorphic features, small hands with proximally placed thumbs, and mild learning issues. This is the smallest deletion of chromosome 12q12 reported to date, and lends further support to the hypothesis that YAF2 may contribute to growth retardation and that PRICKLE1 may play a role in learning disabilities, as originally proposed by Failla et al. [2008].
The patient is a 14-month-old former 34-week male born to a 27-year-old G1P0 mother and a 46-year-old father. Both parents are Caucasian and consanguinity was denied. There were no prenatal complications and ultrasounds were unremarkable, without intrauterine growth retardation. The patient was born at 34 weeks by normal spontaneous vaginal delivery. Birth weight was 1.76 kg (10th to 25th centile corrected for gestational age). Other birth parameters were not available. He was in the neonatal intensive care unit for 2 weeks due to feeding issues, but he had no respiratory issues.
After discharge the patient had progressive growth issues. His weight at 4 months was 50th centile corrected for gestational age (5.76 kg) but fell to <5th centile corrected for gestational age