ROHHAD

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD syndrome) is a very rare disease affecting approximately only 75 cases worldwide. Patients with ROHHAD, as well as patients with Congenital Central Hypoventilation Syndrome (CCHS)^[1] have damage to the mechanism governing proper breathing. ROHHAD syndrome is a disease that is potentially lethal and incurable. Fifteen patients with ROHHAD were evaluated by Diego Ize-Ludlow et al. work published in 2007.^[2]

Pathogenesis

Central hypoventilation syndrome is a heterogeneous group of seemingly overlapping diseases. Paired-like homeobox 2B (PHOX2B) was confirmed in 2009 as the disease-causing gene in patients with congenital central hypoventilation syndrome (CCHS),^[3] a condition present in newborns. This genetic mutation is not present though in those with late-onset central hypoventilation syndrome and hypothalamic dysfunction.^[4]

Symptoms

The variable presentation of ROHHAD includes the following main symptoms:^[4]

• Hyperphagia and obesity by age of 10 years - (median age 3 years);^[2]
• Respiratory Manifestations:
  • Alveolar Hypoventilation (median onset age 6.2 years);^[2]
  • Cardiorespiratory arrest;
  • Reduced Carbon Dioxide Ventilatory Response;
  • Obstructive sleep apnea.
• Thermal or other hypothalamic dysregulations, with autonomic dysregulation by median age 3.6 years:^[2]
  • Failed Growth Hormone Stimulation;
  • Adipsic hypernatremia (inability to feel thirst to keep normal hydration);
  • Hypernatremia;
  • Hyperprolactinemia;
  • Hyperphagia;
  • Diabetes insipidus;
  • Ophthalmologic Manifestations;
  • Thermal Dysregulation;
  • Gastrointestinal dysmotility;
  • Altered Perception of Pain;
  • Altered Sweating;
  • Cold Hands and Feet.
• Neurobehavioral disorders;
• Tumors of neural crest origin.

Clinically overlapping cases exist because CCHS phenotype can also include autonomic nervous system dysregulation, or tumors of neural crest origin.^[4]

Prognosis and treatment

Currently there are no official tests or treatments for ROHHAD. Each child has the symptoms above at different ages, yet most symptoms are eventually present. Many children are misdiagnosed or are never diagnosed until alveolar hypoventilation occurs.

See also

• LO-CHS/HD or LOCHS/HD
• Congenital Central Hypoventilation Syndrome (or CCHS)
• Prader-Willi syndrome

References

1. Congenital Central Hypoventilation Syndrome
2. Ize-Ludlow D, Gray JA, Sperling MA, et al. (July 2007). "Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation presenting in childhood". Pediatrics 120 (1): e179–88. doi:10.1542/peds.2006-3324. PMID 17606542.
3. Lee P, Su YN, Yu CJ, Yang PC, Wu HD (February 2009). "PHOX2B mutation-confirmed congenital central hypoventilation syndrome in a Chinese family: presentation from newborn to adulthood". Chest 135 (2): 537–44. doi:10.1378/chest.08-1664. PMID 19201717.
4. Bougnères P, Pantalone L, Linglart A, Rothenbühler A, Le Stunff C (October 2008). "Endocrine manifestations of the rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, and neural tumor syndrome in childhood". J. Clin. Endocrinol. Metab. 93 (10): 3971–80. doi:10.1210/jc.2008-0238. PMID 18628522.