Chromosome 2p12-P11.2 Deletion Syndrome

A number sign (#) is used with this entry because it represents a contiguous gene deletion syndrome.

Clinical Features

Prasher et al. (1993) reported a 32-year-old man with mental retardation associated with an interstitial deletion of chromosome 2p13-p11.2 detected by G-banding studies. He had delayed psychomotor development as an infant and was a long-term resident in a hospital for the mentally handicapped. He had dysmorphic facial features, such as long narrow face, prominent nose and nasal bridge, micrognathia, high-arched palate, and low-set abnormal ears. He also had restriction of finger movement and hypertonia of the lower limbs with a spastic gait.

Los et al. (1994) reported a boy with de novo interstitial deletion of chromosome 2p12-p11.2 who had dysmorphic features, psychomotor retardation, vitiligo, and disturbed distribution of immunoglobulin (Ig) light chain expression without clinical or laboratory signs of antibody deficiency or other immune disorders. Additional features included cryptorchidism and hypospadias.

Wenger and McPherson (1997) reported a male Amish infant with mildly dysmorphic features and features suggestive of a connective tissue defect who had a de novo interstitial deletion of chromosome 2p13-p11.2 detected by G-banding. Features included beaked nose with abnormal bridge, deep-set eyes with myopia, high narrow palate, low-set abnormal ears, scoliosis, pectus carinatum, and long slender fingers with flexion contractures. He was also reported to have spasticity and hypertonia. He died at age 2 months.

Lacbawan et al. (1999) reported a 12-month-old boy with psychomotor retardation and mild dysmorphic features who had a de novo interstitial deletion of chromosome 2p13-p11.2. He had a flat, broad nose with slightly upturned nares, high-arched palate, mild micrognathia, simple cupped ears, hypotonia, and sensorineural hearing loss.

Barber et al. (2005) reported a child with delayed mental development, mildly dysmorphic features, such as frontal bossing and low-set dysmorphic ears, and recurrent Wilms tumor (194070) who was found to have an interstitial deletion of chromosome 2p12-p11.2. The deletion was inherited from the mother, who had similar dysmorphic features as well as mild learning and speech difficulties. In contrast, Barber et al. (2005) reported 2 additional unrelated families transmitting interstitial deletions encompassing chromosome 2p12-p11.2, but these 2 families were not associated with phenotypic consequences.

Tzschach et al. (2009) reported a 5-year-old girl with an interstitial deletion of chromosome 2p12-p11.2 determined by high-resolution array comparative genomic hybridization (CGH). She had mental retardation, microcephaly, mild dolichocephaly, short stature, pectus carinatum, and clubfeet. Facial features included low-set ears, broad nasal bridge, and frontal bossing. Tzschach et al. (2009) noted that 6 patients with deletions in chromosome 2p12-p11.2 had been previously reported but that there were no consistent common findings apart from developmental delay/mental retardation. However, most of the deletions were analyzed by banding, except for that reported by Barber et al. (2005).

Writzl et al. (2009) reported a 6-year-old boy with delayed development and marked speech delay associated with a de novo interstitial deletion of chromosome 2p12-p11.2. Dysmorphic features included prominent occiput, high forehead, long face, horizontal palpebral fissures, broad high nasal bridge, broad ridge and tip, thin upper vermilion border, and large, protruding ears. He also had bilateral fifth finger clinodactyly, hyperreflexia of the lower limbs with wide-based gait, and bilateral vesicoureteral reflux.

Cytogenetics

Barber et al. (2005) reported 2 unrelated families transmitting interstitial deletions encompassing chromosome 2p12-p11.2 with no phenotypic consequences. In contrast, 2 individuals from a family with a more centromeric 7.5-Mb deletion on chromosome 2p12-p11.2 had mild dysmorphic features and learning and speech disabilities. Barber et al. (2005) noted that the more centromeric area of 2p11.2 was G-band light, indicating a gene-rich region.

By karyotype and array CGH analyses, Tzschach et al. (2009) identified a 11.4-Mb deletion of chromosome 2p12-p11.2 in a girl with mental retardation and mild facial dysmorphism. The deleted region includes the REEP1 gene (609139), haploinsufficiency of which causes spastic paraplegia-31 (SPG31; 610250).

By array CGH analysis, Writzl et al. (2009) determined that the deletion in their patient was 10.43-Mb on chromosome 2p12-p11.2 (76.854 to 87.287 Mb).