Open Access Research BMJ Open: first published as 10.1136/bmjopen-2015-009537 on 29 April 2016. Downloaded from HUWE1 mutations in Juberg-Marsidi and Brooks syndromes: the results of an X-chromosome exome sequencing study Michael J Friez,1 Susan Sklower Brooks,2 Roger E Stevenson,1 Michael Field,3 Monica J Basehore,1 Lesley C Adès,4 Courtney Sebold,5 Stephen McGee,1 Samantha Saxon,1 Cindy Skinner,1 Maria E Craig,4 Lucy Murray,3 Richard J Simensen,1 Ying Yzu Yap,6 Marie A Shaw,6 Alison Gardner,6 Mark Corbett,6 Raman Kumar,6 Matthias Bosshard,7 Barbara van Loon,7 Patrick S Tarpey,8 Fatima Abidi,1 Jozef Gecz,6 Charles E Schwartz1 To cite: Friez MJ, Brooks SS, ABSTRACT et al Strengths and limitations of this study Stevenson RE, . HUWE1 Background: X linked intellectual disability (XLID) mutations in Juberg-Marsidi syndromes account for a substantial number of males ▪ and Brooks syndromes: the Using the power of next generation sequencing, with ID. Much progress has been made in identifying results of an X-chromosome we have linked Juberg-Marsidi syndrome ( JMS) exome sequencing study. the genetic cause in many of the syndromes described and Brooks syndrome as allelic conditions. – BMJ Open 2016;6:e009537. 20 40 years ago. Next generation sequencing (NGS) ▪ This study provides better organisation to the doi:10.1136/bmjopen-2015- has contributed to the rapid discovery of XLID genes field of X linked disorders by providing evidence 009537 and identifying novel mutations in known XLID genes that JMS is not caused by mutation in the ATRX for many of these syndromes. gene. ▸ Prepublication history and Methods: 2 NGS approaches were employed to ▪ We provide clinical descriptions and compari- additional material is identify mutations in X linked genes in families with sons to support our conclusions. available. To view please visit XLID disorders. 1 involved exome sequencing of genes ▪ The reported missense mutations have detrimen- the journal (http://dx.doi.org/ on the X chromosome using the Agilent SureSelect tal effects on HUWE1 functional activity. 10.1136/bmjopen-2015- Human X Chromosome Kit. The second approach was ▪ Based on the limited number of patients/families, 009537). to conduct targeted NGS sequencing of 90 known we are unable to make specific genotype–pheno- http://bmjopen.bmj.com/ XLID genes. type correlations at this time. Results: We identified the same mutation, a c.12928 Received 13 January 2016 G>C transversion in the HUWE1 gene, which gives rise Revised 1 April 2016 to a p.G4310R missense mutation in 2 XLID disorders: Accepted 8 April 2016 have been assigned at least provisional roles Juberg-Marsidi syndrome ( JMS) and Brooks 24 syndrome. Although the original families with these in these syndromes. Some syndromes, ini- disorders were considered separate entities, they tially believed to be separate conditions, have indeed overlap clinically. A third family was also found now been lumped together while others that to have a novel HUWE1 mutation. appeared to be the same have been sepa- on September 29, 2021 by guest. Protected copyright. Conclusions: As we identified a HUWE1 mutation in rated on the basis of molecular an affected male from the original family reported by findings.2356 Juberg and Marsidi, it is evident the syndrome does Juberg-Marsidi syndrome ( JMS) has here- not result from a mutation in ATRX as reported in the tofore been considered by some observers to literature. Additionally, our data indicate that JMS and be allelic to α-thalassemia intellectual disabil- HUWE1 Brooks syndromes are allelic having the same ity (ATRX syndrome) while Brooks syndrome mutation. (aka Brooks-Wisniewski-Brown syndrome) has – been considered to be distinct from JMS.7 10 A missense mutation in ATRX has been previ- ously reported in a family considered to have INTRODUCTION JMS.8 On clinical re-evaluation of the ori- In the two decades since the discovery of the ginal family reported by Juberg and Marsidi,7 fi For numbered affiliations see trinucleotide repeat expansion in FMR1 we considered the ndings in the sole end of article. responsible for fragile X syndrome, substan- affected male still alive to be inconsistent tial progress has been made in defining the with ATRX syndrome. While there are some Correspondence to other X linked intellectual disability (XLID) similarities between JMS and ATRX syn- 1–3 7 Dr Michael J Friez; syndromes at the molecular level. drome, there are distinctive differences. [email protected] Mutations in over 100 X-chromosome genes Specifically, the surviving male in the Friez MJ, et al. BMJ Open 2016;6:e009537. doi:10.1136/bmjopen-2015-009537 1 Open Access BMJ Open: first published as 10.1136/bmjopen-2015-009537 on 29 April 2016. Downloaded from Juberg-Marsidi family had bifrontal narrowing, hypote- function. Marked skewing (>90:10) of X chromosome lorism, prominent nose with overhanging columella, inactivation in all carrier females provided a plausible and thin lips, all facial manifestations very different than reason for absence of clinical manifestations. One those of ATRX syndrome. Subsequently, we identified in carrier subsequently had an affected son. He had this male, a novel missense alteration in HUWE1, a gene growth retardation when delivered at 38 weeks with a located at Xp11.23 that encodes an E3 ubiquitin ligase weight of 1510 g, head circumference of 30 cm and that regulates numerous proteins, such as key cellular length of 42 cm, all measurements less than the third factors p53 and Mcl1.11 12 The identical missense alter- centile for 38 weeks. He had hypotelorism, small appear- ation in HUWE1 was also identified and shown to prop- ing eyes, flat nasal bridge, right cleft lip and palate, erly segregate in another XLID syndrome reported by supravalvar aortic stenosis, small hands and feet, exter- Brooks et al.10 The clinical phenotypes in the two condi- nally rotated feet and undescended testes. Ultrasound tions previously considered to be unrelated show close examination of the brain showed a small cyst similarity. Here, we update the clinical and molecular (1.0×1.6 cm) within each lateral ventricle. He failed the findings in these two families and report an additional newborn hearing test. family with another missense mutations in HUWE1. Clinical update: K9223 (original Brooks syndrome family) Clinical findings in two affected brothers and a nephew METHODS were generalised intrauterine and postnatal growth Informed consent retardation, severe intellectual disability, triangular- The authors note that we have obtained proper shaped face, low posterior hairline, bifrontal narrowness, informed consent from the participants (or parental malar flatness, blepharophimosis, optic atrophy, esotro- consent for participants under 18 years of age) for use pia, nystagmus, bulbous nose, low-set and cupped ears, of their personal information, including photos, for pub- short philtrum, thin tented upper lip and pectus excava- lication purposes. Copies of these consents have been tum (figure 1B).10 They were poorly coordinated and fi shared with the of ce of the Editor. became self-abusive, hyperactive and spastic with large joint contractures. Families The pedigree and clinical findings were updated in Clinical update: K9149 (original JMS family) 2010. The affected males were aged 23, 45 and 52 years. Clinical findings in four affected males in three genera- All growth parameters remained well below the third tions included generalised growth retardation, severe centile. Affected males became ambulatory by about age intellectual disability, tall forehead, epicanthus, short 3 years, but remained non-verbal or had very limited fi fl palpebral ssures, pale retina, at nasal bridge, large or speech (table 1). Hearing loss was believed to be related http://bmjopen.bmj.com/ cupped ears, small penis with undescended testes and to recurrent otitis media. Cranial imaging showed deafness.7 The two brothers in generation II died in enlarged ventricles and small brain. infancy or childhood. Three carrier females had normal intellectual func- The pedigree and clinical findings were updated in tion and showed no phenotypic abnormalities. 2006. The nephew (III-2 in figure 1A), age 27 years, was X-inactivation was markedly skewed (>90:10) in the two found to have moderate hearing loss of unknown type carriers who were informative at the AR locus. but believed to be related to recurrent otitis media, severe growth impairment (all measurements below the Clinical report: family 3 on September 29, 2021 by guest. Protected copyright. third centile) and intellectual disability (IQ<20). Family 3 consists of two brothers, now aged 10 and Craniofacial findings included facial asymmetry, bifron- 13 years (II-5 and II-4 in figure 1C), who have severe tal narrowing, furrowing of the forehead, prominent intellectual disability, microcephaly and postnatal growth brow giving the eyes and midface a sunken appearance, failure. The brothers have three sisters, one of whom hypotelorism, upslanting palpebral fissures, prominent has minor literacy problems. Their mother also has a nose with overhanging columella, long philtrum and minor learning difficulty, not present in her three broth- thin lips with a beak at the midpoint of the upper lip ers and sister. X-inactivation testing in the mother and (figure 1). Additional features were brachydactyly, the daughter with literacy problems was uninformative. decreased musculature of the distal legs, foot deform- The two brothers were born at term gestation with ation (right foot everted, left foot with midfoot varus), weights and lengths at term at or below the third scoliosis, flexion of the hips, genu vara, soft loose skin centile, being 2.52 and 2.67 kg and 44 and 47 cm, over the hands and hyperextensible joints. Sexual hair respectively. Neither was microcephalic at birth but have and penis appeared normal but the testes were not palp- been less than third centile since early childhood.