Hyperpigmentation
Dyskeratosis congenita - Patients may develop diffuse hypo or hyperpigmentation. Lacy reticular pigmentation of the upper chest and neck also occurs. Other cutaneous findings include nail dystrophy and oral leukoplakia.
Fanconi pancytopenia - This is an AR inherited bone marrow failure syndrome. Patients may develop skin hyperpigmentation and café au lait spots. Additional features include short stature, radial hypoplasia, microcephaly, renal and genital anomalies, mental retardation, and characteristic facial features. Neutropenia secondary to marrow failure occurs in 95% of patients (T and B cell immunity is normal).
Nijmegen breakage syndrome - Patients may develop café au lait spots as well as vitiligo. Patients have microcephaly, bird-like facies, and predisposition to cancer. The combined immunodeficiency is characterized by hypogammaglobulinemia and low T cell numbers/function.
Bloom syndrome - Patients develop patchy areas of hypopigmentation or hyperpigmentation, most commonly on the trunk. Patients may also develop telangiectatic erythema on sun exposed areas of the face (similar to a butterfly rash in SLE) which can be bright red and disfiguring in extreme cases.
Schimke Immuno-Osseous Dysplasia
Schimke Immuno-Osseous Dysplasia - Patients develop multiple hyperpigmented macules (lentigines) measuring a few millimeters mainly on the trunk and extremities.