Clinical Guidance

Classes of pathogenic variants. An analysis of the two main phenotypes in 30 individuals with molecularly proven OCA4 identified the following :

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Diagnostic Criteria

To date, no consensus clinical diagnostic criteria for oculocutaneous albinism type 4 (OCA4) have been published.

Suggestive Findings

OCA4 should be considered in probands with the following clinical findings and family history. Clinical findings. Most individuals with OCA4 are recognized within the first year of life because of the following findings.

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Differential Diagnosis

The differential diagnosis of oculocutaneous albinism type 4 (OCA4) includes other genes that cause nonsyndromic oculocutaneous albinism (OCA) and ocular albinism (see Oculocutaneous Albinism and Ocular Albinism Overview) and syndromic OCA (see Hermansky-Pudlak syndrome and Chediak-Higashi syndrome). FRMD7-related infantile nystagmus, an X-linked disorder characterized by either the onset of horizontal, conjugate, gaze-dependent nystagmus in the first six months of life or periodic alternating nystagmus of infantile onset, can also be considered in the differential diagnosis. FRMD7-related infantile nystagmus can be distinguished from OCA4 by the absence of OCA.

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Management Guidelines

To date, no clinical practice guidelines for oculocutaneous albinism type 4 (OCA4) have been published. In the absence of published guidelines, the following recommendations are based on the authors' personal experience managing individuals with this disorder.

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs in an individual diagnosed with OCA4, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended.

Table 2.

Oculocutaneous Albinism Type 4: Recommended Evaluations Following Initial Diagnosis

System/Concern | Evaluation | Comment

Vision

| Complete ophthalmologic eval | Incl assessment of:

• Best corrected visual acuity

• Refractive errors

• Strabismus

Skin | By dermatologist | To instruct in use of sun-protective clothing topical sunscreens

Genetic counseling

| By genetics professionals1 | To obtain a pedigree inform affected persons their families re nature, MOI, implications of OCA4 to facilitate medical personal decision making

Family support

resources | By clinicians, wider care team, family support organizations | Assessment of family social structure to determine need for:

• Community or such as Parent to Parent

• Social work involvement for parental support

• Home nursing referral

MOI = mode of inheritance; OCA4 = oculocutaneous albinism type 4

1. Clinical geneticist, certified genetic counselor, certified genetic nurse, genetics advanced practice provider (nurse practitioner or physician assistant)

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Clinical Guidance

Avoid the following:

• Prolonged exposure of the skin to the sun

• Activities without appropriate eye protection from the sun

• Tanning beds and artificial ultraviolet sources

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Therapies Under Investigation

Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.

Source: GeneReviews — "Oculocutaneous Albinism Type 4"

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the following evaluations are recommended:

• Annual ophthalmologic examinations and reassessment for accurate correction of refractive errors are appropriate.

• Although there are no definitive guidelines supported by scientific evidence as to the frequency that an individual should be evaluated by a dermatologist, skin evaluation for cancer screening every six months is recommended.

Source: GeneReviews — "Oculocutaneous Albinism Type 4"