Wiedemann-Steiner Syndrome: Case Report and Review of Literature

Abstract

Wiedemann-Steiner syndrome (WDSTS) is an autosomal dominant disorder with a broad and variable phenotypic spectrum characterized by intellectual disability, prenatal and postnatal growth retardation, hypertrichosis, characteristic facial features, behavioral problems, and congenital anomalies involving different systems. Here, we report a five-year-old boy who was diagnosed with WDSTS based on the results of Trio-based whole-exome sequencing and an assessment of his clinical features. He had intellectual disability, short stature, hirsutism, and atypical facial features, including a low hairline, down-slanting palpebral fissures, hypertelorism, long eyelashes, broad and arching eyebrows, synophrys, a bulbous nose, a broad nasal tip, and dental/oral anomalies. However, not all individuals with WDSTS exhibit the classic phenotype, so the spectrum of the disorder can vary widely from relatively atypical facial features to multiple systemic symptoms. Here, we summarize the clinical and molecular spectrum, diagnosis and differential diagnosis, long-term management, and care planning of WDSTS to improve the awareness of both pediatricians and clinical geneticists and to promote the diagnosis and treatment of the disease.

Keywords: KMT2A; Wiedemann–Steiner syndrome; intellectual disability.

Figure 1

Physical characteristics of a 5-year-old boy with WDSTS. (a) Thick hair, rib eversion flagging, and special facial features, including low hairline, down-slanting palpebral fissures, long eyelashes, broad and arching brows, synophrys, bulbous nose, and a large nasal tip. (b) Hypertrichosis on the back and upper limbs. (c) Hypertrichosis on the lower limbs.

Figure 2

Analysis of the pathogenic genetic mutation in the patient (a) This patient’s family tree. The unaffected man and female are represented by a blank square and circle, respectively. The filled square represents the afflicted male while the arrow represents the proband. (b) Sanger sequencing confirmed a heterozygous KMT2A c.7009C>T (red arrow). At this nucleotide, both parents had the wild-type sequence.

Figure 3

The X-axis represents the number of participants and the Y-axis represents the clinical features. The colored boxes indicate affected individuals, the dark gray boxes indicate unaffected individuals, and the light gray boxes denote data not available.