Clinical Description
White-Sutton syndrome is a neurodevelopmental disorder characterized by a wide spectrum of cognitive dysfunction, developmental delays (particularly in speech and language acquisition), and autism spectrum disorder (ASD) as well as other behavioral problems. Additional features commonly reported include hypotonia, gastrointestinal problems, seizures, microcephaly, sensorineural hearing loss, strabismus, short stature, tendency towards obesity, and sleep disturbance (particularly sleep apnea).
To date, more than 90 individuals have been identified with a pathogenic variant in POGZ [Gulsuner et al 2013, Gilissen et al 2014, Iossifov et al 2014, Deciphering Developmental Disorders Study Group 2015, Fukai et al 2015, Homsy et al 2015, Ye et al 2015, Hashimoto et al 2016, Stessman et al 2016, Tan et al 2016, White et al 2016, Dentici et al 2017, Du et al 2018, Ferretti et al 2019, Zhao et al 2019, Assia Batzir et al 2020, Pascolini et al 2020, Samanta et al 2020, Dal et al 2021, Donnarumma et al 2021, Garde et al 2021, Liu et al 2021, Trimarchi et al 2021, Türay & Eröz 2021, Wright et al 2022]. Table 2 and the following description of the phenotypic features associated with this condition are based on these reports.
Table 2.
Select Features of White-Sutton Syndrome
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Feature | # of Persons w/Feature | Comment |
---|
Intellectual disability /
Learning difficulties
| 76/76 (100%) | LD in 5/19 persons Mild ID in 8/19 Moderate ID in 3/19 Severe ID in 3/19 1
|
Speech delay
| 74/74 (100%) | |
Motor delay
| 61/76 (80%) | |
Hypotonia
| 34/44 (77%) | |
Behavioral problems
|
ASD
| 33/73 (45%) | Plus at least 4 addl persons w/some features consistent w/ASD |
Other
| 46/78 (59%) | Biting & aggression toward others, anxiety, stereotypies, withdrawal, hyperactivity, obsessions |
Epilepsy
| 11/71 (15%) | GTC, partial seizures, drop attacks, absence Plus 2 addl persons w/paroxysmal nonepileptic episodes
|
Ophthalmologic features
| 40/64 (63%) | |
Hearing loss
| 28/74 (38%) | |
Sleep disorders
| 18/63 (29%) | |
Feeding &
gastrointestinal problems
|
Feeding difficulties
| 23/44 (52%) | |
Constipation
| 17/56 (30%) | |
Cyclic vomiting
| 11/52 (21%) | Plus 1 person w/vomiting w/o features of CVS |
Diaphragmatic hernia
| 3/83 (4%) | |
Other GI disorders
| 6/71(8%) | Intestinal malrotation, pancreatitis, rectal prolapse, ventral hernia, occlusion (presumed to be intestinal obstruction) 2 |
Genitourinary abnormalities
|
Urinary tract involvement
| 5/48 (10%) | Megaureter, duplicated collecting system |
Male genital abnormalities
| 6/51 (12%) males | Cryptorchidism, hypoplastic testes, micropenis |
Musculoskeletal anomalies
| 22/71 (31%) | |
Based on Fukai et al [2015], Ye et al [2015], Stessman et al [2016], Wang et al [2016], White et al [2016], Dentici et al [2017], Ferretti et al [2019], Zhao et al [2019], Assia Batzir et al [2020], Samanta et al [2020], Garde et al [2021], and Trimarchi et al [2021]
ASD = autism spectrum disorder; CVS = cyclic vomiting syndrome; GTC = generalized tonic-clonic; ID = intellectual disability; LD = learning difficulties
- 1.
- 2.
"Occlusion" as appears in Garde et al [2021]; interpreted by authors as "intestinal obstruction"
Intellectual disability / learning difficulties. Virtually all individuals reported to date have learning difficulties or intellectual disability ranging from mild (36%-50%) to profound (≤32%). Assessment of various cognitive domains in five individuals identified deficiencies in language and attention, as well as executive and social dysfunction that affected their daily lives (especially in communication) [Garde et al 2021]. Although information on cognitive function in adults is limited, some adults are able to work, care for themselves, and raise children [Assia Batzir et al 2020; Garde et al 2021; Liu et al 2021; Wright et al 2022; Authors, personal experience].
Speech delay is seen in nearly all affected individuals, and is generally more pronounced than motor delays. While first words often emerge at an appropriate age, the formation of sentences may be delayed until the school-age years; some remain nonverbal after age six years [Assia Batzir et al 2020, Garde et al 2021]. Despite language difficulties, verbal comprehension appears to be less affected.
Although information on cognitive function in adults is limited, adults may be able to work and care for themselves, and in some instances raise children [Assia Batzir et al 2020; Garde et al 2021; Liu et al 2021; Wright et al 2022; Authors, personal experience].
Motor delay is common. Reported age at onset of walking ranges from before 12 months to six years [Assia Batzir et al 2020, Garde et al 2021]. Delays may be related to hypotonia that presents as early as the first days of life. Hypotonia is seen in the vast majority of individuals and may be the first sign that brings the child to medical attention.
Additional causes for motor delays include medical issues such as complex abdominal surgery and lower limb spasticity. Gait abnormalities including clumsiness and difficulty with coordination have also been reported.
Although a movement disorder is not frequently seen, paroxysmal nonepileptic events have been described in at least two individuals [Ferretti et al 2019, Donnarumma et al 2021].
Behavior problems include issues with attention, anxiety, irritability, and aggression toward oneself or others. In their assessment of neuropsychological profiles of 19 individuals with White-Sutton syndrome, Garde et al [2021] observed common behavioral characteristics including immature behavior (7 individuals), significant slowness (7), and attention disorder (8) that were associated with either excessive inhibition and withdrawal or lack of inhibition leading to agitation, opposition, or provocation.
ASD was observed in up to 50% of individuals reported in the literature. Repetitive behaviors [Wang et al 2016], restricted interests, and stereotypic movements of the hands or mouth have been described [Stessman et al 2016, Dentici et al 2017, Donnarumma et al 2021].
Epilepsy. Both generalized and tonic and focal epilepsy, as well as febrile seizures and EEG abnormalities without overt convulsions, occur in approximately 20% of affected individuals [Pascolini et al 2020, Samanta et al 2020]. Epileptic seizures precipitated by bathing/showering in hot water were reported in one individual [Türay & Eröz 2021].
While onset of seizures ranges from infancy to adolescence, it is typically between ages one and four years. Seizures are generally controlled either by monotherapy or with multiple anti-seizure medications, and may resolve with age. Status epilepticus has not been reported.
Information on EEG patterns is limited. Findings may include epileptic abnormalities localized to the frontal region or bitemporal sharp waves and are not specific to this disorder [Stessman et al 2016, White et al 2016, Ferretti et al 2019, Samanta et al 2020].
Neuroimaging. Brain imaging reveals central nervous system abnormalities in up to two thirds of affected individuals. When present, brain MRI abnormalities are variable and nonspecific. Recurring features include small foci in the deep white matter on T2/FLAIR imaging, prominence of cerebrospinal fluid in the posterior fossa, and cerebellar dysgenesis [Samanta et al 2020]. Thin corpus callosum, abnormal myelination, polymicrogyria, small optic chiasm / optic nerve hypoplasia, persistent cavum septum pellucidum, and Dandy-Walker spectrum malformations have also been described [Ye et al 2015, Dentici et al 2017, Assia Batzir et al 2020, Samanta et al 2020].
Ophthalmologic abnormalities that can impair vision include retinal dystrophy (3 individuals) [White et al 2016, Assia Batzir et al 2020], optic nerve hypoplasia (3) [White et al 2016, Assia Batzir et al 2020], Horner syndrome (2) [Gilissen et al 2014, White et al 2016], and coloboma (1) [White et al 2016]. Treatable conditions can include refractive errors (astigmatism, myopia, or hyperopia) and strabismus.
Hearing loss, reported in approximately one third of individuals, can be conductive secondary to recurrent middle ear infections or sensorineural with cochlear dysfunction.
Sleep disorders. Families of individuals with White-Sutton syndrome often report problems with sleep (e.g., difficulty falling asleep, frequent awakenings, sleepwalking).
Sleep apnea is known to occur; a sleep disorder survey completed for 12 individuals revealed features suggestive of obstructive sleep apnea in four [Assia Batzir et al 2020].
Feeding/gastrointestinal problems. Feeding difficulties, which are common, may be severe enough to require nasogastric tube feeding or gastrostomy. These problems can be related to gastroesophageal reflux, feeding intolerance with gastric distention, problems with chewing or swallowing, or oversensitivity of the oral region resulting in food aversion.
Vomiting is common. Some individuals experience recurring episodes of vomiting in childhood with or without a cyclical pattern. Vomiting tends to improve or resolve with age; some parents report that nausea and vomiting appear to respond to therapies for "abdominal migraines" [Assia Batzir et al 2020; Authors, personal communication].
Gastrointestinal manifestations requiring surgery can include intestinal malrotation, ventral and inguinal hernia, and rectal prolapse.
Congenital diaphragmatic hernia, although infrequently described, is a recurring finding [White et al 2016, Longoni et al 2017, Assia Batzir et al 2020, Garde et al 2021].
Genitourinary abnormalities. Congenital anomalies of the kidneys and urinary tract can include dysplastic kidneys as well as duplicated collecting system, hydronephrosis, and/or megaureter. Male genital anomalies can include undescended testes, hypoplastic scrotum/testes, and micropenis.
Recurrent infections. Frequent respiratory, ear, and bladder infections were reported in several individuals; one individual was diagnosed with immune deficiency. One individual had low titers to vaccines [Authors, personal experience].
Musculoskeletal. Minor abnormalities of the fingers and toes (e.g., brachydactyly, broad thumbs or first toes, and spatulate fingers) and joint laxity may be seen. Clubfeet, joint contractures, and syndactyly are rare.
Growth. Although growth parameters at birth are usually within the normal range, intrauterine growth restriction has been documented in approximately 20% of individuals for whom data were available.
Height and weight range from below the third percentile to above average. Short stature or failure to gain weight have been reported in approximately 15% of individuals [Fukai et al 2015, Stessman et al 2016, Tan et al 2016, Dentici et al 2017, Ferretti et al 2019, Zhao et al 2019, Assia Batzir et al 2020, Pascolini et al 2020, Garde et al 2021].
Despite initial problems with feeding, a significant proportion of children become overweight, as early as the first years of life [Stessman et al 2016].
Microcephaly (head circumference <3rd percentile) is common.
Other. Although minor cardiovascular abnormalities including atrial septal defect / patent foramen ovale, bicuspid aortic valve, and mild dilatation of the ascending aorta have been reported, it is unclear if these occur at a higher frequency in White-Sutton syndrome than in the general population.
Craniofacial features may include microcephaly, brachycephaly, high and broad forehead, hypertelorism, broad and/or high nasal root, anteverted nares, long malar region with midface hypoplasia/retrusion, prognathism, downturned corners of the mouth, palate abnormalities (high-arched palate, cleft palate, bifid uvula), and low-set ears. While these facial features are frequently observed, the authors believe that a definitive clinical diagnosis of this syndrome cannot be made based solely on facial or other phenotypic features.
Prognosis. It is unknown whether life span in individuals with White-Sutton syndrome is decreased. The oldest known individual was age 36 years at time of report [Wright et al 2022]. One affected individual (age not reported) has an affected son, age 15 years [Liu et al 2021]. Instances of parent-to-child transmission [Assia Batzir et al 2020, Garde et al 2021, Liu et al 2021] demonstrate that survival into adulthood and raising a family are possible.