Clinical Guidance
The clinical features reported in individuals with 16p12.2 recurrent deletion include developmental delay, intellectual disability, and neurobehavioral/psychiatric manifestations. Some individuals have epilepsy, microcephaly, growth deficiency, congenital heart defects, and hearing loss . One study included 23 unrelated probands with 16p12.2 recurrent deletion from a postnatal clinical genetic testing cohort . A second study analyzed 141 children with 16p12.2 deletion (median age: 7 years) referred for clinical genetic testing . A third analyzed 124 probands with 16p12.2 recurrent deletion referred for clinical genetic testing and their family members , including individuals reported by . Because of the nature of these cohorts, the frequency of reported features likely reflects an ascertainment bias. Studies of adults with 16p12.2 recurrent deletion in which participants were not ascertained for developmental delays report different phenotypes (e.g., schizophrenia , impaired cognition , autism , epilepsy , and obesity-related features ). Table 2. 16p12.2 Recurrent Deletion: Frequency of Select Features
Feature | % of Persons w/Feature1 | Comments |
|---|
psychiatric manifestations | Speech delay | 82% |
Global developmental delay | 81% | Mild to profound |
Learning disability | 70% | — |
Intellectual disability | 69% | Mild to profound; cognitive development can be normal |
Expressive language disorder | 65% | — |
Motor delay | 65% | — |
Trouble concentrating | 56% | — |
Autism spectrum disorder | 44% | — |
Sleep disturbance | 41% | — |
Aggression | 39% | — |
ADHD | 38% | — |
Anxiety | 33% | — |
Neurologic | Hypotonia | 39% |
Lack of coordination | 37% | — |
Abnormal gait | 29% | — |
Muscle weakness | 28% | — |
Excessive drooling | 23% | — |
Seizures | 20% | — |
Gastrointestinal | Constipation | 36% |
Feeding difficulty | 31% | — |
Gastroesophageal reflux | 22% | — |
Growth | Microcephaly | 26% |
Growth deficiency | 24% | — |
Other | Pes planus | 29% |
Dental issues | 29% | — |
Dry skin or psoriasis | 23% | — |
Frequent infection | 22% | — |
Undescended testes | 17% | — |
Obesity | 14% | ADHD = attention-deficit/hyperactivity disorder Based on , , 1. Developmental delay can range from mild to profound . Speech delay is common, and some individuals remain nonverbal into childhood and adolescence. Motor milestones can also be delayed and many individuals have global delays. |
Source: GeneReviews — "16p12.2 Recurrent Deletion"
