del(16)(p11p12.2)

Epidemiology and Etiology:

· 0.05% of DD

· NAHR due to numerous seg dups

Common sites:

·

Gross features:

· Hypotonia

· Growth delay (some)

· Craniofacial

· Flat facies

· Deep-set eyes

· Downslanting and short palpebral fissures

· Broad nasal bridge

· Anteverted or short, upturned nares

· Low-set and malformed ears, posteriorly rotated

· Open mouth with drooling (some)

· Nonspecific digital findings

· Single palmar creases

· Mild cutaneous syndactyly

· Brachydactyly

· Camptodactyly

· Cardiac defects (some)

· Café au lait macules (some)

Histologic features:

·

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

· Common distal breakpoint at 16p12.2 (21.4 Mb NCBI 36.1)

· Variable proximal breakpoints between 28.5 and 30.1 Mb (NCBI 36.1)

· Minimal deleted region (7.1 Mb) contains 33 RefSeq genes

· OTOA (autosomal recessive deafness)

· CLN3 (Batten disease, AR)

· Pathogenesis not known at this time

Other features:

· DD (significant)

· Feeding difficulties with GERD in infancy

· Frequent ear infections

· Insensitivity to pain (some)

· Sleep disturbance / apnea

References:

· Slavotinek AM. Novel microdeletion syndromes detected by chromosome microarrays. Hum. Genet. 2008;124(1):1-17.