title: Elucidating the behavioral phenotype of patients affected with mucolipidosis IV: What can we learn from the parents?
abstract: BACKGROUND
  Mucolipidosis type IV (ML-IV) is a rare autosomal recessive lysosomal storage disorder which presents with nonspecific developmental delay. Nowadays with the use of new tools such as next generation sequencing, more ML-IV affected patients are diagnosed. Still, identifying the behavioral phenotype might be of help for early diagnosis and anticipatory guidance, as well as for counseling of the families.
  
  
  OBJECTIVE
  Identification of the behavioral characteristics of 12 ML-IV patients, aged from 2.5 to 34 years, based on their caregivers' observations.
  
  
  METHODS
  The information was gathered from the patients' parents using an extensive semi-structured interview especially designed for this study. Each interview lasted approximately three hours.
  
  
  RESULTS
  Patients were uniformly described as friendly and show explicit pleasure from both social interactions and music. They all presented delays in psychomotor development, while their general health was reported as good. Parents reported that the patients present deterioration of motor and communication skills over the years. Episodes of ocular pain, with ipsilateral flushing of the face and tearing were frequently reported, as was shortening of the Achilles tendon. Since the identification of the ML-IV gene, diagnosis is made earlier in life.
  
  
  CONCLUSIONS
  We suggest that ML-IV be considered in the differential diagnosis of patients with developmental delay, who present the behavioral phenotype reported here. This pattern could also be useful for the ancitipatory guidance in the care of ML-IV affected patients. Further clinical research is warranted to confirm these preliminary findings.
authors.affiliation: Department of Psychology, Hebrew University, Jerusalem, Israel.
authors.forename: Perri
authors.initials: P
authors.lastname: Segal
authors.affiliation: Institute of Rare Diseases & Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; The Dr. Pinchas Borenstein Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel.
authors.forename: Ben
authors.initials: B
authors.lastname: Pode-Shakked
authors.affiliation: Institute of Rare Diseases & Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel; The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. Electronic address: Annick.Rothschild@sheba.health.gov.il.
authors.forename: Annick
authors.initials: A
authors.lastname: Raas-Rothschild
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002652:Child Behavior; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills; D009081:Mucolipidoses / Q000175:diagnosis* / Q000235:genetics; D010290:Parents; D010641:Phenotype; D012919:Social Behavior; D050051:Transient Receptor Potential Channels / Q000235:genetics
chemical_list: C416674:MCOLN1 protein, human; D050051:Transient Receptor Potential Channels
keywords: Behavior; MCOLN1; Mucolipidosis type IV