Discussion
2q37 deletion syndrome first appeared in the literature in 1989. Since
then, approximately 74 children and adults have been presented in the
medical literature with 2q37 gene deletion with no additional
chromosomal involvement [8]. In 2004, US geneticist Dr. Kari Casas
described 66 cases in addition to describing 6 case reports [8].
2q37 deletion syndrome is a rare disease that has affected around 100
reported cases worldwide [9]. The deletion results in developmental
delay, brachydactyly of the third to fifth digits and/or toes, obesity,
short stature, change of facial appearance, and an autism spectrum
disorder [3]. Patients with deletion syndrome also have some form of
mental retardation [10].
We report an American female patient with a 2q37.3 deletion that was
confirmed by comparative genomic hybridization (CGH) plus single
nucleotide polymorphism (SNP). Although clinical presentation is
variable, almost all patients have some degree of mental retardation and
facial dysmorphism. The patient presented with easy fatigability, gross
motor delay, and low muscle tone. An echo was performed, which revealed
a patent foramen ovale with a left-to-right shunt. A cardiovascular exam
found that the heart experienced strong peripheral pulses with a brisk
capillary refill. The patient is otherwise healthy with no dysmorphic
features. The HEENT exam revealed a clear oropharynx with moist mucous
membranes.
Congenital heart defects have been found in around 20% of patients with
2q37 deletion syndrome. Both septal defects and aortic coarctation have
been described in patients with 2q37 deletion syndrome [3]. The
patient presented does not have aortic coarctation but does suffer from
the presence of a patent foramen ovale in the atrial septum, which was
confirmed using an echo. The ascending aorta, transverse arch, and
descending aorta were also found to be wide open and not blocking blood
flow.
The patient is growing and developing normally, both physically and
mentally. Growth hormone deficiency has been found in 4 patients with
2q37 gene mutations, which led to short stature. All 4 patients
experienced improved growth following growth hormone administration
[11-13].
The better status of the patient who presented with no mental or
physical developmental abnormalities or delays can be attributed to the
size of the deletion. The patient had a gene deletion size of 2.63 MB.
The largest deletion is 10 MB; most are usually greater than 3 MB
[14]. Almost 30% of patients with 2q37 deletion syndrome have major
malformations. These generally include the gastrointestinal, nervous
system, and cardiac abnormalities [3].