Which physical findings are characteristic of homocystinuria?

Updated: Jul 27, 2018
  • Author: Pitchaiah Mandava, MD, PhD; Chief Editor: Helmi L Lutsep, MD  more...
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Answer

Answer

Homocystinuria is associated with the following physical findings:

  • Downward dislocation of lens (ectopia lentis)

  • Marfanoid habitus

  • Pes excavatum, pes carinatum, and genu valgum

  • Mental retardation

  • Signs and symptoms of strokes in any vascular distribution: hemiplegia, aphasia, ataxia, and pseudobulbar palsy are among the most common findings.

Patients with classic homocystinuria may first be recognized because of downward dislocation of the lens (ectopia lentis) [5] , marfanoid habitus, mental retardation [5] , and/or seizures.

Patients with defective methylcobalamin synthesis may have all of these features, along with symptoms of methylmalonic acidemia (see Metabolic Disease and Stroke - Methylmalonic Acidemia).

Acute stroke symptoms may occur in these patients.

Traditional risk factors—hypertension, smoking, and diabetes—may or may not be present.

The oral health of 14 patients with homozygote cystathionine beta synthase-deficient homocystinuria was evaluated in a Swedish study and found to be compromised in a majority of cases. The authors suggested that methionine restriction (low-protein diet) in the treatment of homocystinuria may result in a diet high in sugars. They therefore noted the need for regular dental checkups and preventive oral care for individuals suffering from homocystinuria. In addition, the authors noted that all patients had short dental roots, particularly of the central maxillary incisors. [6]

In a Spanish cross-sectional survey sent to 35 hospitals, 75 patients were identified with homocystinuria: 41 with transsulfuration defects (1 death), 27 with remethylation defects (6 deaths), and 7 without a syndromic diagnosis. In 18 cases, more than one sibling was affected. Patients with remethylation defects had the most severe clinical manifestations. There was a high percentage of cognitive impairment, followed by lens diseases. Neurologic disorders were present in almost half of the patients, and there was increased vascular involvement in CBS-deficient adults. [7]


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