Affected individuals present with a broad array of medical and behavioral manifestations (tables 1 and 2). Patients are consistently characterized by global developmental delay, intellectual disability, speech abnormalities, ASD-like behaviors, hypotonia and mild dysmorphic features. Table 1 summarizes the dysmorphic and medical conditions that have been reported in individuals with PMS. Table 2 summarizes the psychiatric and neurological associated with PMS. Most of the studies include small samples or relied on parental report or medical record review to collect information, which can account in part for the variability in the presentation of some of the presenting features. Larger prospective studies are needed to further characterize the phenotype. + Table 1: dysmorphic features and medical comorbid conditions that have been reported in individuals with Phelan–McDermid<unk>  Dysmorphic feature Percentage (%) Medical comorbidities Percentage (%) Macrocephaly 7–31 Hypothyroidism 3–6 Microcephaly 11–14 Sleep disturbance 41–46 Dolichocephaly 23–86 Gastroesophageal reflux 42–44 Long eyelashes 43–93 Increased pain threshold 10–88 Bulbous nose 47–80 Constipation/diarrhea 38–41 High-arched palate 25–47 Brain imaging abnormalities 7–75 Malocclusion/widely spaced teeth 19 Recurrent upper respiratory infections 8–53 Full cheeks 25 Renal abnormalities 17–26 Pointed chin 22–62 Lymphedema 8–53 Large fleshy hands 33–68 Seizures 14–41 Hypoplastic/dysplastic nails 3–78 Strabismus 6–26 Hyper-extensibility 25–61 Short stature 11–13 Abnormal spine curvature 22 Tall stature/accelerated growth 3–18 Sacral dimple 13–37 Cardiac defects 3–25 Syndactyly of toes 2 and 3 48 Precocious or delayed puberty 12 + Table 2: psychiatric and neurologic manifestations associated with Phelan–McDermid<unk>  Psychiatric and neurologic manifestations Percentage (%) Autism spectrum disorder >25 Intellectual disability ~100 Global developmental delay ~100 Absent or severely affected speech >75 Sensory seeking behaviors (mouthing of objects) >25 Teeth grinding >25 Hyperactivity and inattention >50 Stereotypical movements >50 Hypotonia >50 Fine and gross motor abnormalities >90 Poor fine motor coordination >90 Gait abnormalities >90 Visual tracking abnormalities >85 Seizure disorder 17–41 Brain structural abnormalities 44–100 Sleep problems >40
22q13 deletion syndrome
13q deletion syndrome
2q37 deletion syndrome
22q11.2 distal deletion syndrome
9q34 deletion syndrome
1q21.1 deletion syndrome
1p36 deletion syndrome
22q11.2 duplication syndrome