WRS is characterized by an Aged appearance at birth and deficiency or absence of the layer of fat under the skin (subcutaneous lipoatrophy). As a result, the skin may appear unusually thin, fragile, dry, shiny, wrinkled, and aged. Certain veins and muscles may be abnormally prominent, particularly those of the forehead. For unknown reasons, as affected infants age, abnormal deposits of fat may accumulate under the skin (subcutaneous) in lower (caudal) areas of the body, particularly around the buttocks, the areas around the genitals and the anus (anogenital area), and the area between the ribs and the hips (flanks). In addition, in infants and children with the disorder, the abdomen may appear unusually large and prominent.
In individuals with WRS, Growth delays may occur before birth (intrauterine growth retardation), particularly during the last three months (third trimester) of fetal development. The Growth delays will continue well after birth (postnatal). Patients with WRS also experience poor weight gain, and failure to thrive through their lifetime. In addition, in some cases, affected infants may experience swallowing (dysphagia) and feeding difficulties that may contribute to Growth delays and failure to thrive.
Progressive neurological deterioration may occur in WRS. The specific symptoms may vary from person to person as affected individuals may not have all of the symptoms listed below.
Infants and children with WRS also have distinctive abnormalities of the head and face (craniofacial). In many affected individuals, the soft spot in the front of the skull (anterior) may be abnormally large and wide, and its closure may be unusually delayed. The fibrous gaps between other bones in the skull (cranial sutures) may also be abnormally wide. In addition, in infants with the disorder, bones of the forehead (frontal bones) and the sides of the skull (parietal bones) are abnormally prominent (frontal and bi-parietal bossing), while the facial bones are unusually small and underdeveloped (hypoplastic).
Such abnormalities may cause the head to appear unusually large (pseudohydrocephalus). In affected infants and children, distinctive facial abnormalities may include an unusually small mouth (microstomia); a prominent chin, and low-set ears that are abnormally angled toward the back of the head (posteriorly angulated). Facial features typically appear unusually small when compared with the large forehead and sides of the skull. In addition, affected infants may have an unusually small, distinctively “beak-shaped” nose that becomes more pronounced with advancing age.
In most infants and children with WRS, additional craniofacial abnormalities are also present. Affected infants may have two to four front teeth (neonatal incisors), which fall out during the course of early infancy. Subsequent tooth development (dentition) is delayed and impaired. In addition, in infants and children with the disorder, the lower eyelids may droop or turn outward (ectropion), exposing the thin, delicate mucous membranes that line the eyelids as well as a portion of the eyeballs (conjunctivae). In one patient, spastic entropion, a condition in which the eyelid turns inward so that the eyelashes and skin rub against the eye surface, was also described. An interesting feature in a few cases is that the lower eyelids may cover more than the lower half of the eyeball as if the eyelids are situated higher than expected. Affected infants and children may also have unusually sparse scalp hair, eyebrows, and eyelashes. (hypotrichosis). In a family with three affected siblings, various Eye abnormalities including cataract, cloudy cornea, perforation of cornea, and microphthalmia (unusually small size of the eye) also were noted.
Infants and children with WRS may also have distinctive abnormalities affecting the hands, feet, arms, and legs (extremities). The arms and legs are abnormally thin, the hands and feet are disproportionately large; and the fingers and toes are long with unusually small, incompletely developed (atrophic) or thickened (dystrophic) nails. The joints are thick and rigid, especially in the shoulders, elbows and knees. Recent MRI (magnetic resonance imaging) studies have confirmed the presence of normal amounts of subcutaneous truncal fat, and marked loss of fat from the face and distal extremities. Bone thinning (osteopenia) may predispose to bony fractures. Bone progenitor cell transformation to bone (osteoblasts) and cartilage cells (chondrocytes) are also impaired. The lack of cellular differentiation capacity in WRS patients may be responsible for the clinical appearance and symptoms of this rare disorder.
Most infants and children with the disorder also have varying degrees of intellectual disability, which may range from mild to severe. However, a few children have demonstrated near normal mental development. During infancy, affected individuals may begin to experience progressive neurological and neuromuscular abnormalities. In most patients, there are severe delays in the acquisition of skills requiring the coordination of physical and mental activities (psychomotor retardation). In addition, in many cases, infants and children with the disorder lack head control, exhibit Diminished muscle tone (hypotonia), and have an impaired ability to coordinate voluntary movements of the chest and abdominal areas (truncal ataxia). For example, they may have difficulty controlling the range of movements during certain muscular actions and may experience rhythmic, involuntary tremors when performing certain movements (intention tremor). Infants and children with the disorder may also experience rapid, involuntary, horizontal movements of the eyes (horizontal nystagmus) and limited clearness (acuity) of vision. Infants may have dysphonic, horse cry and older children may have an unusual high-pitched voice.
In addition, investigators have reported that neurological deterioration observed in a few individuals with WRS may be associated with loss of the myelin sheath from nerve fibers (demyelization) within the white substance of the brain (e.g., pure sudanophilic leukodystrophy). Myelin is a whitish fatty substance that forms a protective wrapping or “sheath” around certain nerve fibers (axons) and serves as an electrical insulator, enabling the effective transmission of nerve impulses. “White substance” within the brain and spinal cord (central nervous system) primarily consists of bundles of myelinated nerve fibers. The majority of patients with WRS did not have leukodystrophy at the age ascertained. Dandy Walker malformation and ventriculomegaly, basal ganglia calcification, and agenesis of corpus callosum were reported.
The lack of subcutaneous fat tissue has prompted researchers to compare WRS with generalized lipodystrophy (Berardinelli) syndrome. Laboratory studies, however, in those cases examined, have shown no elevation of fasting glucose, lipids, or insulin, as would be expected in Berardinelli syndrome. A few patients however, had elevated triglyceride levels. Fat pads are localized at the flank, rather than at the buttocks, which is specific for this syndrome, but also can be seen in carbohydrate deficient glycoprotein syndrome (CDG). Individuals with WRS may also develop abnormal side-to-side curvature of the spine (scoliosis). In addition, infants and children with WRS are often prone to recurrent respiratory infections, which may result in life-threatening complications.
In one of the few cases where post mortem pathology was performed, an almost total absence of the mesentery, a tissue that anchors the small intestines to the back of the abdominal wall, and absence of the mesocolon, the tissue that secures the transverse portion of the large intestines, were found.