Cystic fibrosis (CF) is a multisystem disease affecting epithelia of the respiratory tract, exocrine pancreas, intestine, hepatobiliary system, and exocrine sweat glands. Morbidities include recurrent sinusitis and bronchitis, progressive obstructive pulmonary disease with bronchiectasis, exocrine pancreatic deficiency and malnutrition, pancreatitis, gastrointestinal manifestations (meconium ileus, rectal prolapse, distal intestinal obstructive syndrome), liver disease, diabetes, male infertility due to hypoplasia or aplasia of the vas deferens, and reduced fertility or infertility in some women. Pulmonary disease is the major cause of morbidity and mortality in CF.

Tracheobronchiomegaly is characterized by striking dilatation of the intrathoracic trachea and of the major bronchi (summary by Johnston and Green, 1965).

T-cell immunodeficiency with thymic aplasia (TIDTA) is an autosomal recessive disorder that is often detected at birth through newborn SCID screening with the finding of decreased T-cell receptor excision circles (TRECs). Affected individuals have selective hypo- or aplasia of the thymus, which results in T-cell immunodeficiency due to impaired T-cell development and increased susceptibility to viral infections. The phenotype is similar to T-/B+/NK+ SCID. Some patients may die in childhood; thymus transplantation may be curative (summary by Du et al., 2019).

Primary immunodeficiency syndrome due to p14 deficiency is characterised by short stature, hypopigmentation, coarse facies and frequent bronchopulmonary <i>Streptococcus pneumoniae</i> infections.

Poikiloderma with neutropenia (PN) is characterized by an inflammatory eczematous rash (ages 6-12 months) followed by post-inflammatory poikiloderma (age >2 years) and chronic noncyclic neutropenia typically associated with recurrent sinopulmonary infections in the first two years of life and (often) bronchiectasis. There is increased risk for myelodysplastic syndrome and, rarely, acute myelogenous leukemia. Other ectodermal findings include nail dystrophy and palmar/plantar hyperkeratosis. Most affected individuals also have reactive airway disease and some have short stature, hypogonadotropic hypogonadism, midfacial retrusion, calcinosis cutis, and non-healing skin ulcers.

MPSPS is an autosomal recessive inborn error of metabolism resulting in a multisystem disorder with features of the mucopolysaccharidosis lysosomal storage diseases (see, e.g., 607016). Patients present in infancy or early childhood with respiratory difficulties, cardiac problems, anemia, dysostosis multiplex, renal involvement, coarse facies, and delayed psychomotor development. Most patients die of cardiorespiratory failure in the first years of life (summary by Kondo et al., 2017).